1
|
Morera H, Dave P, Kolinko Y, Alahmari S, Anderson A, Denham G, Davis C, Riano J, Goldgof D, Hall LO, Harry GJ, Mouton PR. A novel deep learning-based method for automatic stereology of microglia cells from low magnification images. Neurotoxicol Teratol 2024; 102:107336. [PMID: 38402997 DOI: 10.1016/j.ntt.2024.107336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/31/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024]
Abstract
Microglial cells mediate diverse homeostatic, inflammatory, and immune processes during normal development and in response to cytotoxic challenges. During these functional activities, microglial cells undergo distinct numerical and morphological changes in different tissue volumes in both rodent and human brains. However, it remains unclear how these cytostructural changes in microglia correlate with region-specific neurochemical functions. To better understand these relationships, neuroscientists need accurate, reproducible, and efficient methods for quantifying microglial cell number and morphologies in histological sections. To address this deficit, we developed a novel deep learning (DL)-based classification, stereology approach that links the appearance of Iba1 immunostained microglial cells at low magnification (20×) with the total number of cells in the same brain region based on unbiased stereology counts as ground truth. Once DL models are trained, total microglial cell numbers in specific regions of interest can be estimated and treatment groups predicted in a high-throughput manner (<1 min) using only low-power images from test cases, without the need for time and labor-intensive stereology counts or morphology ratings in test cases. Results for this DL-based automatic stereology approach on two datasets (total 39 mouse brains) showed >90% accuracy, 100% percent repeatability (Test-Retest) and 60× greater efficiency than manual stereology (<1 min vs. ∼ 60 min) using the same tissue sections. Ongoing and future work includes use of this DL-based approach to establish clear neurodegeneration profiles in age-related human neurological diseases and related animal models.
Collapse
Affiliation(s)
- Hunter Morera
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA.
| | - Palak Dave
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - Yaroslav Kolinko
- Department of Histology and Embryology & Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic
| | - Saeed Alahmari
- Department of Computer Science, Najran University, Najran 66462, Saudi Arabia
| | | | | | | | | | - Dmitry Goldgof
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - Lawrence O Hall
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA
| | - G Jean Harry
- Mechanistic Toxicology Branch, Division of Translational Toxicology, NIEHS/NIH, Research Triangle Park, NC 27709, USA
| | - Peter R Mouton
- Department of Computer Science and Engineering, University of South Florida, Tampa, FL 33620, USA; SRC Biosciences, Tampa, FL 33606, USA.
| |
Collapse
|
2
|
Harry GJ. Developmental Associations between Neurovascularization and Microglia Colonization. Int J Mol Sci 2024; 25:1281. [PMID: 38279280 PMCID: PMC10816009 DOI: 10.3390/ijms25021281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 01/28/2024] Open
Abstract
The temporal and spatial pattern of microglia colonization and vascular infiltration of the nervous system implies critical associated roles in early stages of nervous system development. Adding to existing reviews that cover a broad spectrum of the various roles of microglia during brain development, the current review will focus on the developmental ontogeny and interdependency between the colonization of the nervous system with yolk sac derived macrophages and vascularization. Gaining a better understanding of the timing and the interdependency of these two processes will significantly contribute to the interpretation of data generated regarding alterations in either process during early development. Additionally, such knowledge should provide a framework for understanding the influence of the early gestational environmental and the impact of genetics, disease, disorders, or exposures on the early developing nervous system and the potential for long-term and life-time effects.
Collapse
Affiliation(s)
- G Jean Harry
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, Durham, NC 27709, USA
| |
Collapse
|
3
|
Massri AJ, Fitzpatrick M, Cunny H, Li JL, Harry GJ. Differential gene expression profiling implicates altered network development in rat postnatal day 4 cortex following 4-Methylimidazole (4-MeI) induced maternal seizures. Neurotoxicol Teratol 2023; 100:107301. [PMID: 37783441 PMCID: PMC10843020 DOI: 10.1016/j.ntt.2023.107301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/31/2023] [Accepted: 09/19/2023] [Indexed: 10/04/2023]
Abstract
Compromised maternal health leading to maternal seizures can have adverse effects on the healthy development of offspring. This may be the result of inflammation, hypoxia-ischemia, and altered GABA signaling. The current study examined cortical tissue from F2b (2nd litter of the 2nd generation) postnatal day 4 (PND4) offspring of female Harlan SD rats chronically exposed to the seizuregenic compound, 4-Methylimidazole (0, 750, or 2500 ppm 4-MeI). Maternal seizures were evident only at 2500 ppm 4-MeI. GABA related gene expression as examined by qRT-PCR and whole genome microarray showed no indication of disrupted GABA or glutamatergic signaling. Canonical pathway hierarchical clustering and multi-omics combinatory genomic (CNet) plots of differentially expressed genes (DEG) showed alterations in genes associated with regulatory processes of cell development including neuronal differentiation and synaptogenesis. Functional enrichment analysis showed a similarity of cellular processes across the two exposure groups however, the genes comprising each cluster were primarily unique rather than shared and often showed different directionality. A dose-related induction of cytokine signaling was indicated however, pathways associated with individual cytokine signaling were not elevated, suggesting an alternative involvement of cytokine signaling. Pathways related to growth process and cell signaling showed a negative activation supporting an interpretation of disruption or delay in developmental processes at the 2500 ppm 4-MeI exposure level with maternal seizures. Thus, while GABA signaling was not altered as has been observed with maternal seizures, the pattern of DEG suggested a potential for alteration in neuronal network formation.
Collapse
Affiliation(s)
- Abdull J Massri
- Integrative Bioinformatics, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Mackenzie Fitzpatrick
- Mechanistic Toxicology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Helen Cunny
- Office of the Scientific Director, Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - Jian-Liang Li
- Integrative Bioinformatics, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA
| | - G Jean Harry
- Mechanistic Toxicology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, 111 T. W. Alexander Drive, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
4
|
Martinez M, Harry GJ, Haynes EN, Lin PID, Oken E, Horton MK, Wright RO, Arora M, Austin C. Quantitative fluoride imaging of teeth using CaF emission by laser induced breakdown spectroscopy. J Anal At Spectrom 2023; 38:303-314. [PMID: 36776552 PMCID: PMC9906802 DOI: 10.1039/d2ja00134a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/15/2022] [Indexed: 05/18/2023]
Abstract
In this work, we propose the use of molecular emission of calcium fluoride (CaF) by laser induced breakdown spectroscopy (LIBS) to obtain quantitative fluoride distribution images of teeth. LIBS has proved to be an efficient technique to detect low amounts of fluoride in solids, and human teeth have the advantage being a matrix rich in calcium. We used new calibration material from sintered hydroxyapatite pellets doped with fluoride to determine the optimized LIBS conditions of argon flow at 1 L min-1 and using the green emission bands of CaF in 530 nm, and obtained a calibration curve between 0 and 400 μg g-1, and LOD of 18 μg g-1. This methodology was applied within a rat model of fluoride exposure and showed increasing tooth-fluoride with increased exposure dose. To demonstrate applicability of this method in human teeth, we quantified fluoride distribution in teeth from three children from non-fluorinated and fluorinated water regions. Samples from children living in fluoridated water regions showed higher fluoride concentrations in dentine formed after birth, compared to a child from a non-fluoridated region. Teeth have been used as biomarkers for environmental exposure and this new method opens the opportunity in epidemiology research to study critical windows of early life exposure to fluoride as well.
Collapse
Affiliation(s)
- Mauro Martinez
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai New York NY USA
| | - G Jean Harry
- Mechanistic Toxicology Branch, Division of National Toxicology Program, National Institute of Environmental Health Sciences Research Triangle Park NC USA
| | - Erin N Haynes
- Department of Epidemiology, College of Public Health, University of Kentucky Lexington KY USA
| | - Pi-I D Lin
- Division of Chronic Disease Research Across the Life Course, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute Boston MA USA
| | - Emily Oken
- Division of Chronic Disease Research Across the Life Course, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute Boston MA USA
| | - Megan K Horton
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai New York NY USA
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai New York NY USA
| | - Manish Arora
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai New York NY USA
| | - Christine Austin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai New York NY USA
| |
Collapse
|
5
|
McPherson CA, Kelly-Rajan K, Lefebvre d’Hellencourt C, Harry GJ. High Content Imaging and Quantification of Microglia Phagocytosis In Vitro. Curr Protoc 2023; 3:e638. [PMID: 36622815 PMCID: PMC10035415 DOI: 10.1002/cpz1.638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Microglia function as the tissue-specific resident macrophages of the nervous system, performing immune and non-immune functions. These functions are critical to development and to maintain homeostasis in the nervous system throughout the lifespan, and during brain injury or disease. One method by which microglia maintain homeostasis is phagocytosis of aberrant proteins, extracellular debris, synapses, or apoptotic cells. Phagocytic function can be changed by environmental or genetic risk factors that affect microglia. These protocols present a rapid and simple in vitro high-content imaging protocol for studying phagocytosis in the murine microglia BV-2 cell line. High-content imaging and analysis enable versatility of the assay, which can be used to test multiple experimental conditions, or as a screening tool. © 2023 Wiley Periodicals LLC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. Basic Protocol 1: Phagocytosis of fluorescently labeled particles Basic Protocol 2: Examining modifications to phagocytosis by test substances Basic Protocol 3: High content imaging and analysis of phagocytic cells.
Collapse
Affiliation(s)
- Christopher A. McPherson
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Kiran Kelly-Rajan
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Christian Lefebvre d’Hellencourt
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France
| | - G. Jean Harry
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| |
Collapse
|
6
|
Martin NP, Jean Harry G. Imaging Inflammasome Activation in Microglia. Curr Protoc 2022; 2:e578. [PMID: 36286528 PMCID: PMC9614552 DOI: 10.1002/cpz1.578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Inflammasomes are multiprotein complexes that play key roles in the host's innate immune response to insult. The assembly of an inflammatory complex is initiated with the oligomerization of the upstream inflammasome-forming sensor and then follows a well-orchestrated multi-step process leading to downstream effector functions that are critical in the innate immune response. The final assembly of these steps provides a detectable readout of inflammasome complex activation in the form of an apoptosis-associated speck-like protein containing a CARD (ASC) speck. Inflammasome activation-and the release of IL-1β and ASC specks from the microglia, the brain resident immune cell-have been implicated in various neurological and neurodegenerative disorders. Protocols exist for the generation of fluorescent inflammasome indicator peripheral macrophages. Building upon these protocols, we describe here a protocol that details the generation of fluorescent inflammasome indicator microglia cells using recombinant retroviruses to transduce murine BV-2 cells. In this protocol, the cells are established in a manner to allow for experimental control of the initial priming step of the inflammasome activation process. We then provide a series of steps for using these reporter cells within an inflammasome activation assay and use real-time imaging of ASC-speck formation as an indicator of inflammasome activation. In addition, we describe strategies for using these cells for examining the effects of a test substance on inflammasome activation. This protocol offers an effective approach conducive to screening for and examining modifications of microglia inflammasome activation due to exposure to chemicals or pharmacological agents. © Published 2022. This article is a U.S. Government work and is in the public domain in the USA. Basic Protocol 1: Production of retroviruses to express inflammasome indicator Basic Protocol 2: Generation of inflammasome indicator BV-2 cells Basic Protocol 3: Priming and activation of BV-2-ASC-Cerulean cells for inflammasome activation assay Basic Protocol 4: Examining modifications to inflammasome activation by test substances Basic Protocol 5: Imaging and analysis of ASC speck formation.
Collapse
Affiliation(s)
- Negin P. Martin
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| | - G. Jean Harry
- Mechanistic Toxicology Branch, Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| |
Collapse
|
7
|
Petroff RL, Williams C, Li JL, MacDonald JW, Bammler TK, Richards T, English CN, Baldessari A, Shum S, Jing J, Isoherranen N, Crouthamel B, McKain N, Grant KS, Burbacher TM, Harry GJ. Prolonged, Low-Level Exposure to the Marine Toxin, Domoic Acid, and Measures of Neurotoxicity in Nonhuman Primates. Environ Health Perspect 2022; 130:97003. [PMID: 36102641 PMCID: PMC9472675 DOI: 10.1289/ehp10923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 07/21/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The excitotoxic molecule, domoic acid (DA), is a marine algal toxin known to induce overt hippocampal neurotoxicity. Recent experimental and epidemiological studies suggest adverse neurological effects at exposure levels near the current regulatory limit (20 ppm, ∼0.075-0.1mg/kg). At these levels, cognitive effects occur in the absence of acute symptoms or evidence of neuronal death. OBJECTIVES This study aimed to identify adverse effects on the nervous system from prolonged, dietary DA exposure in adult, female Macaca fascicularis monkeys. METHODS Monkeys were orally exposed to 0, 0.075, and 0.15mg/kg per day for an average of 14 months. Clinical blood counts, chemistry, and cytokine levels were analyzed in the blood. In-life magnetic resonance (MR) imaging assessed volumetric and tractography differences in and between the hippocampus and thalamus. Histology of neurons and glia in the fornix, fimbria, internal capsule, thalamus, and hippocampus was evaluated. Hippocampal RNA sequencing was used to identify differentially expressed genes. Enrichment of gene networks for neuronal health, excitotoxicity, inflammation/glia, and myelin were assessed with Gene Set Enrichment Analysis. RESULTS Clinical blood counts, chemistry, and cytokine levels were not altered with DA exposure in nonhuman primates. Transcriptome analysis of the hippocampus yielded 748 differentially expressed genes (fold change≥1.5; p≤0.05), reflecting differences in a broad molecular profile of intermediate early genes (e.g., FOS, EGR) and genes related to myelin networks in DA animals. Between exposed and control animals, MR imaging showed comparable connectivity of the hippocampus and thalamus and histology showed no evidence of hypomyelination. Histological examination of the thalamus showed a larger microglia soma size and an extension of cell processes, but suggestions of a GFAP+astrocyte response showed no indication of astrocyte hypertrophy. DISCUSSION In the absence of overt hippocampal excitotoxicity, chronic exposure of Macaca fascicularis monkeys to environmentally relevant levels of DA suggested a subtle shift in the molecular profile of the hippocampus and the microglia phenotype in the thalamus that was possibly reflective of an adaptive response due to prolonged DA exposure. https://doi.org/10.1289/EHP10923.
Collapse
Affiliation(s)
- Rebekah L. Petroff
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Christopher Williams
- Mechanistic Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Jian-Liang Li
- Epigenetics & Stem Cell Biology Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - James W. MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Theo K. Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Todd Richards
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | | | - Audrey Baldessari
- Washington National Primate Research Center, Seattle, Washington, USA
| | - Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Jing Jing
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
- Center on Human Development and Disability, University of Washington, Seattle, Washington, USA
| | - Brenda Crouthamel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Noelle McKain
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Kimberly S. Grant
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
- Washington National Primate Research Center, Seattle, Washington, USA
| | - Thomas M. Burbacher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
- Washington National Primate Research Center, Seattle, Washington, USA
- Center on Human Development and Disability, University of Washington, Seattle, Washington, USA
| | - G. Jean Harry
- Mechanistic Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| |
Collapse
|
8
|
Harry GJ, McBride S, Witchey SK, Mhaouty-Kodja S, Trembleau A, Bridge M, Bencsik A. Roadbumps at the Crossroads of Integrating Behavioral and In Vitro Approaches for Neurotoxicity Assessment. Front Toxicol 2022; 4:812863. [PMID: 35295216 PMCID: PMC8915899 DOI: 10.3389/ftox.2022.812863] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/25/2022] [Indexed: 12/15/2022] Open
Abstract
With the appreciation that behavior represents the integration and complexity of the nervous system, neurobehavioral phenotyping and assessment has seen a renaissance over the last couple of decades, resulting in a robust database on rodent performance within various testing paradigms, possible associations with human disorders, and therapeutic interventions. The interchange of data across behavior and other test modalities and multiple model systems has advanced our understanding of fundamental biology and mechanisms associated with normal functions and alterations in the nervous system. While there is a demonstrated value and power of neurobehavioral assessments for examining alterations due to genetic manipulations, maternal factors, early development environment, the applied use of behavior to assess environmental neurotoxicity continues to come under question as to whether behavior represents a sensitive endpoint for assessment. Why is rodent behavior a sensitive tool to the neuroscientist and yet, not when used in pre-clinical or chemical neurotoxicity studies? Applying new paradigms and evidence on the biological basis of behavior to neurobehavioral testing requires expertise and refinement of how such experiments are conducted to minimize variability and maximize information. This review presents relevant issues of methods used to conduct such test, sources of variability, experimental design, data analysis, interpretation, and reporting. It presents beneficial and critical limitations as they translate to the in vivo environment and considers the need to integrate across disciplines for the best value. It proposes that a refinement of behavioral assessments and understanding of subtle pronounced differences will facilitate the integration of data obtained across multiple approaches and to address issues of translation.
Collapse
Affiliation(s)
- G. Jean Harry
- Neurotoxicology Group, Molecular Toxicology Branch, Division National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
- *Correspondence: G. Jean Harry,
| | - Sandra McBride
- Social & Scientific Systems, Inc., a DLH Holdings Company, Durham, NC, United States
| | - Shannah K. Witchey
- Division National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Sakina Mhaouty-Kodja
- Sorbonne Université, CNRS, INSERM, Neuroscience Paris Seine – Institut de Biologie Paris Seine, Paris, France
| | - Alain Trembleau
- Sorbonne Université, CNRS UMR8246, Inserm U1130, Institut de Biologie Paris Seine (IBPS), Neuroscience Paris Seine (NPS), Paris, France
| | - Matthew Bridge
- Social & Scientific Systems, Inc., a DLH Holdings Company, Durham, NC, United States
| | - Anna Bencsik
- Anses Laboratoire de Lyon, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), Université de Lyon 1, Lyon, France
| |
Collapse
|
9
|
Malecki KMC, Andersen JK, Geller AM, Harry GJ, Jackson CL, James KA, Miller GW, Ottinger MA. Integrating Environment and Aging Research: Opportunities for Synergy and Acceleration. Front Aging Neurosci 2022; 14:824921. [PMID: 35264945 PMCID: PMC8901047 DOI: 10.3389/fnagi.2022.824921] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/12/2022] [Indexed: 12/25/2022] Open
Abstract
Despite significant overlaps in mission, the fields of environmental health sciences and aging biology are just beginning to intersect. It is increasingly clear that genetics alone does not predict an individual’s neurological aging and sensitivity to disease. Accordingly, aging neuroscience is a growing area of mutual interest within environmental health sciences. The impetus for this review came from a workshop hosted by the National Academies of Sciences, Engineering, and Medicine in June of 2020, which focused on integrating the science of aging and environmental health research. It is critical to bridge disciplines with multidisciplinary collaborations across toxicology, comparative biology, epidemiology to understand the impacts of environmental toxicant exposures and age-related outcomes. This scoping review aims to highlight overlaps and gaps in existing knowledge and identify essential research initiatives. It begins with an overview of aging biology and biomarkers, followed by examples of synergy with environmental health sciences. New areas for synergistic research and policy development are also discussed. Technological advances including next-generation sequencing and other-omics tools now offer new opportunities, including exposomic research, to integrate aging biomarkers into environmental health assessments and bridge disciplinary gaps. This is necessary to advance a more complete mechanistic understanding of how life-time exposures to toxicants and other physical and social stressors alter biological aging. New cumulative risk frameworks in environmental health sciences acknowledge that exposures and other external stressors can accumulate across the life course and the advancement of new biomarkers of exposure and response grounded in aging biology can support increased understanding of population vulnerability. Identifying the role of environmental stressors, broadly defined, on aging biology and neuroscience can similarly advance opportunities for intervention and translational research. Several areas of growing research interest include expanding exposomics and use of multi-omics, the microbiome as a mediator of environmental stressors, toxicant mixtures and neurobiology, and the role of structural and historical marginalization and racism in shaping persistent disparities in population aging and outcomes. Integrated foundational and translational aging biology research in environmental health sciences is needed to improve policy, reduce disparities, and enhance the quality of life for older individuals.
Collapse
Affiliation(s)
- Kristen M. C. Malecki
- Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
- *Correspondence: Kristen M. C. Malecki,
| | | | - Andrew M. Geller
- United States Environmental Protection Agency, Office of Research and Development, Durham, NC, United States
| | - G. Jean Harry
- Division of National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Chandra L. Jackson
- Division of Intramural Research, Department of Health and Human Services, Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
- Department of Health and Human Services, National Institute on Minority Health and Health Disparities, National Institutes of Health, Bethesda, MD, United States
| | - Katherine A. James
- Department of Environmental and Occupational Health, Colorado School of Public Health, University of Colorado Denver, Denver, CO, United States
| | - Gary W. Miller
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, United States
| | - Mary Ann Ottinger
- Department of Biology and Biochemistry, University of Houston, Houston, TX, United States
| |
Collapse
|
10
|
Childers GM, Perry CA, Blachut B, Martin N, Bortner CD, Sieber S, Li JL, Fessler MB, Harry GJ. Assessing the Association of Mitochondrial Function and Inflammasome Activation in Murine Macrophages Exposed to Select Mitotoxic Tri-Organotin Compounds. Environ Health Perspect 2021; 129:47015. [PMID: 33929904 PMCID: PMC8086801 DOI: 10.1289/ehp8314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND Mitochondrial function is implicated as a target of environmental toxicants and found in disease or injury models, contributing to acute and chronic inflammation. One mechanism by which mitochondrial damage can propagate inflammation is via activation of the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family, pyrin domain-containing receptor (NLRP)3 inflammasome, a protein complex that processes mature interleukin (IL)-1β. IL-1β plays an important role in the innate immune response and dysregulation is associated with autoinflammatory disorders. OBJECTIVE The objective was to evaluate whether mitochondrial toxicants recruit inflammasome activation and IL-1β processing. METHOD Murine macrophages (RAW 264.7) exposed to tri-organotins (triethyltin bromide (TETBr), trimethyltin hydroxide (TMTOH), triphenyltin hydroxide (TPTOH), bis(tributyltin)oxide) [Bis(TBT)Ox] were examined for pro-inflammatory cytokine induction. TMTOH and TETBr were examined in RAW 264.7 and bone marrow-derived macrophages for mitochondrial bioenergetics, reactive oxygen species (ROS) production, and inflammasome activation via visualization of aggregate formation, caspase-1 flow cytometry, IL-1β enzyme-linked immunosorbent assay and Western blots, and microRNA (miRNA) and mRNA arrays. RESULTS TETBr and TMTOH induced inflammasome aggregate formation and IL-1β release in lipopolysaccharide (LPS)-primed macrophages. Mitochondrial bioenergetics and mitochondrial ROS were suppressed. Il1a and Il1b induction with LPS or LPS+ATP challenge was diminished. Differential miRNA and mRNA profiles were observed. Lower miR-151-3p targeted cyclic adenosine monophosphate (cAMP)-mediated and AMP-activated protein kinase signaling pathways; higher miR-6909-5p, miR-7044-5p, and miR-7686-5p targeted Wnt beta-catenin signaling, retinoic acid receptor activation, apoptosis, signal transducer and activator of transcription 3, IL-22, IL-12, and IL-10 signaling. Functional enrichment analysis identified apoptosis and cell survival canonical pathways. CONCLUSION Select mitotoxic tri-organotins disrupted murine macrophage transcriptional response to LPS, yet triggered inflammasome activation. The differential response pattern suggested unique functional changes in the inflammatory response that may translate to suppressed host defense or prolong inflammation. We posit a framework to examine immune cell effects of environmental mitotoxic compounds for adverse health outcomes. https://doi.org/10.1289/EHP8314.
Collapse
Affiliation(s)
- Gabrielle M. Childers
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Caroline A. Perry
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Barbara Blachut
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Negin Martin
- Laboratory of Neurobiology, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Carl D. Bortner
- Signal Transduction Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Stella Sieber
- Molecular Genomics Core Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Jian-Liang Li
- Integrative Bioinformatics Support Group, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Michael B. Fessler
- Immunity, Inflammation, and Disease Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - G. Jean Harry
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| |
Collapse
|
11
|
Dobi A, Rosanaly S, Devin A, Baret P, Meilhac O, Harry GJ, d'Hellencourt CL, Rondeau P. Advanced glycation end-products disrupt brain microvascular endothelial cell barrier: The role of mitochondria and oxidative stress. Microvasc Res 2020; 133:104098. [PMID: 33075405 DOI: 10.1016/j.mvr.2020.104098] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/06/2020] [Accepted: 10/14/2020] [Indexed: 12/16/2022]
Abstract
During diabetes mellitus, advanced glycation end-products (AGEs) are major contributors to the development of alterations in cerebral capillaries, leading to the disruption of the blood-brain barrier (BBB). Consequently, this is often associated with an amplified oxidative stress response in microvascular endothelial cells. As a model to mimic brain microvasculature, the bEnd.3 endothelial cell line was used to investigate cell barrier function. Cells were exposed to native bovine serum albumin (BSA) or modified BSA (BSA-AGEs). In the presence or absence of the antioxidant compound, N-acetyl-cysteine, cell permeability was assessed by FITC-dextran exclusion, intracellular free radical formation was monitored with H2DCF-DA probe, and mitochondrial respiratory and redox parameters were analyzed. We report that, in the absence of alterations in cell viability, BSA-AGEs contribute to an increase in endothelial cell barrier permeability and a marked and prolonged oxidative stress response. Decreased mitochondrial oxygen consumption was associated with these alterations and may contribute to reactive oxygen species production. These results suggest the need for further research to explore therapeutic interventions to restore mitochondrial functionality in microvascular endothelial cells to improve brain homeostasis in pathological complications associated with glycation.
Collapse
Affiliation(s)
- Anthony Dobi
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France
| | - Sarah Rosanaly
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France
| | - Anne Devin
- CNRS, Institut de Biochimie et Génétique Cellulaires, UMR 5095, Université de Bordeaux, F-33000 Bordeaux, France
| | - Pascal Baret
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France
| | - Olivier Meilhac
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France; CHU de La Réunion, Centre d'Investigation Clinique, 97400 Saint-Denis, France
| | - G Jean Harry
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, 27709 Research Triangle Park, NC, USA
| | - Christian Lefebvre d'Hellencourt
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France; Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, 27709 Research Triangle Park, NC, USA.
| | - Philippe Rondeau
- Inserm, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), plateforme CYROI, 97490 Sainte-Clotilde, France; Université de La Réunion, UMR 1188, 97490 Sainte-Clotilde, France.
| |
Collapse
|
12
|
Bowen C, Childers G, Perry C, Martin N, McPherson CA, Lauten T, Santos J, Harry GJ. Mitochondrial-related effects of pentabromophenol, tetrabromobisphenol A, and triphenyl phosphate on murine BV-2 microglia cells. Chemosphere 2020; 255:126919. [PMID: 32402876 PMCID: PMC8439439 DOI: 10.1016/j.chemosphere.2020.126919] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/18/2020] [Accepted: 04/27/2020] [Indexed: 05/02/2023]
Abstract
The predominant reliance on bromated flame retardants (BFRs) is diminishing with expanded use of alternative organophosphate flame retardants. However, exposure related issues for susceptible populations, the developing, infirmed, or aged, remain given environmental persistence and home-environment detection. In this regard, reports of flame retardant (FR)-related effects on the innate immune system suggest process by which a spectrum of adverse health effects could manifest across the life-span. As representative of the nervous system innate immune system, the current study examined changes in microglia following exposure to representative FRs, pentabromophenol (PBP), tetrabromobisphenol A (2,2',6,6',-tetrabromo-4,4'-isopropylidine diphenol; TBBPA) and triphenyl phosphate (TPP). Following 18hr exposure of murine BV-2 cells, at dose levels resulting in ≥80% viability (10 and 40 μM), limited alterations in pro-inflammatory responses were observed however, changes were observed in mitochondrial respiration. Basal respiration was altered by PBP; ATP-linked respiration by PBP and TBBPA, and maximum respiration by all three FRs. Basal glycolytic rate was altered by PBP and TBBPA and compensatory glycolysis by all three. Phagocytosis was decreased for PBP and TBBPA. NLRP3 inflammasome activation was assessed using BV-2-ASC (apoptosis-associated speck-like protein containing a CARD) reporter cells to visualize aggregate formation. PBP, showed a direct stimulation of aggregate formation and properties as a NLRP3 inflammasome secondary trigger. TBBPA showed indications of possible secondary triggering activity while no changes were seen with TPP. Thus, the data suggests an effect of all three FRs on mitochondria metabolism yet, different functional outcomes including, phagocytic capability and NLRP3 inflammasome activation.
Collapse
Affiliation(s)
| | | | | | - Negin Martin
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | | | | |
Collapse
|
13
|
Harry GJ, Childers G, Giridharan S, Hernandes IL. An association between mitochondria and microglia effector function. What do we think we know? ACTA ACUST UNITED AC 2020; 7:150-165. [PMID: 32934971 DOI: 10.20517/2347-8659.2020.07] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While resident innate immune cells of the central nervous system, the microglia, represent a cell population unique in origin, microenvironment, and longevity, they assume many properties displayed by peripheral macrophages. One prominent shared property is the ability to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS) upon activation by the pro-inflammatory stimuli lipopolysaccharide. This shift serves to meet specific cellular demands and allows for cell survival, similar to the Warburg effect demonstrated in cancer cells. In contrast, normal survelliance phenotype or stimulation to a non-proinflammatory phenotype relies primarily on OXPHOS and fatty acid oxidation. Thus, mitochondria appear to function as a pivotal signaling platform linking energy metabolism and macrophage polarization upon activation. These unique shifts in cell bioenergetics in response to different stimuli are essential for proper effector responses at sites of infection, inflammation, or injury. Here we present a summary of recent developments as to how these dynamics characterized in peripheral macrophages are displayed in microglia. The new insights provided by an increased understanding of metabolic reprogramming in macrophages may allow for translation to the CNS and a better understanding of microglia heterogeneity, regulation, and function.
Collapse
Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
| | - Gabrielle Childers
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA.,Current affiliation: Gabrielle Childers, University of Alabama, Birmingham, AL
| | - Sahana Giridharan
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA.,Giridharan, Duke University, Durham, NC
| | - Irisyunuel Lopez Hernandes
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
| |
Collapse
|
14
|
Yen K, Wan J, Mehta HH, Miller B, Christensen A, Levine ME, Salomon MP, Brandhorst S, Xiao J, Kim SJ, Navarrete G, Campo D, Harry GJ, Longo V, Pike CJ, Mack WJ, Hodis HN, Crimmins EM, Cohen P. Humanin Prevents Age-Related Cognitive Decline in Mice and is Associated with Improved Cognitive Age in Humans. Sci Rep 2018; 8:14212. [PMID: 30242290 PMCID: PMC6154958 DOI: 10.1038/s41598-018-32616-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/07/2018] [Indexed: 12/30/2022] Open
Abstract
Advanced age is associated with a decline in cognitive function, likely caused by a combination of modifiable and non-modifiable factors such as genetics and lifestyle choices. Mounting evidence suggests that humanin and other mitochondrial derived peptides play a role in several age-related conditions including neurodegenerative disease. Here we demonstrate that humanin administration has neuroprotective effects in vitro in human cell culture models and is sufficient to improve cognition in vivo in aged mice. Furthermore, in a human cohort, using mitochondrial GWAS, we identified a specific SNP (rs2854128) in the humanin-coding region of the mitochondrial genome that is associated with a decrease in circulating humanin levels. In a large, independent cohort, consisting of a nationally-representative sample of older adults, we find that this SNP is associated with accelerated cognitive aging, supporting the concept that humanin is an important factor in cognitive aging.
Collapse
Affiliation(s)
- Kelvin Yen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Junxiang Wan
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Hemal H Mehta
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Brendan Miller
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Amy Christensen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Morgan E Levine
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - Matthew P Salomon
- Department of Translational Molecular Medicine, John Wayne Cancer Institute at Providence Saint John's Health Center, Santa Monica, CA, USA
| | - Sebastian Brandhorst
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Jialin Xiao
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Su-Jeong Kim
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Gerardo Navarrete
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Daniel Campo
- Department of Molecular and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - G Jean Harry
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, Triangle Park, NC, USA
| | - Valter Longo
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Christian J Pike
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Wendy J Mack
- Departments of Medicine and Preventive Medicine, University of Southern California Atherosclerosis Research Unit, University of Southern California, Los Angeles, CA, USA
| | - Howard N Hodis
- Departments of Medicine and Preventive Medicine, University of Southern California Atherosclerosis Research Unit, University of Southern California, Los Angeles, CA, USA
| | - Eileen M Crimmins
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Pinchas Cohen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
15
|
Goulding DR, Nikolova VD, Mishra L, Zhuo L, Kimata K, McBride SJ, Moy SS, Harry GJ, Garantziotis S. Inter-α-inhibitor deficiency in the mouse is associated with alterations in anxiety-like behavior, exploration and social approach. Genes Brain Behav 2018; 18:e12505. [PMID: 29987918 DOI: 10.1111/gbb.12505] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 06/26/2018] [Accepted: 07/06/2018] [Indexed: 12/30/2022]
Abstract
In recent years, several genome-wide association studies have identified candidate regions for genetic susceptibility in major mood disorders. Most notable are regions in a locus in chromosome 3p21, encompassing the genes NEK4-ITIH1-ITIH3-ITIH4. Three of these genes represent heavy chains of the composite protein inter-α-inhibitor (IαI). In order to further establish associations of these genes with mood disorders, we evaluated behavioral phenotypes in mice deficient in either Ambp/bikunin, which is necessary for functional ITIH1 and ITIH3 complexes, or in Itih4, the gene encoding the heavy chain Itih4. We found that loss of Itih4 had no effect on the behaviors tested, but loss of Ambp/bikunin led to increased anxiety-like behavior in the light/dark and open field tests and reduced exploratory activity in the elevated plus maze, light/dark preference and open field tests. Ambp/bikunin knockout mice also exhibited a sex-dependent exaggeration of acoustic startle responses, alterations in social approach during a three-chamber choice test, and an elevated fear conditioning response. These results provide experimental support for the role of ITIH1/ITIH3 in the development of mood disorders.
Collapse
Affiliation(s)
- David R Goulding
- Comparative Medicine Branch, Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Viktoriya D Nikolova
- Carolina Institute for Developmental Disabilities and Department of Psychiatry, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Lopa Mishra
- Center for Translational Medicine, Department of Surgery, Georgetown University, Washington, District of Columbia
| | - Lisheng Zhuo
- Multidisciplinary Pain Center and the Research Creation Support Center, Aichi Medical University, Nagakute, Japan
| | - Koji Kimata
- Multidisciplinary Pain Center and the Research Creation Support Center, Aichi Medical University, Nagakute, Japan
| | | | - Sheryl S Moy
- Carolina Institute for Developmental Disabilities and Department of Psychiatry, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - G J Harry
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Stavros Garantziotis
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| |
Collapse
|
16
|
McPherson CA, Zhang G, Gilliam R, Brar SS, Wilson R, Brix A, Picut C, Harry GJ. An Evaluation of Neurotoxicity Following Fluoride Exposure from Gestational Through Adult Ages in Long-Evans Hooded Rats. Neurotox Res 2018; 34:781-798. [PMID: 29404855 PMCID: PMC6077107 DOI: 10.1007/s12640-018-9870-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/11/2018] [Accepted: 01/12/2018] [Indexed: 01/04/2023]
Abstract
At elevated levels, fluoride (F-) exposure has been associated with adverse human health effects. In rodents, F- exposure has been reported to induce deficits in motor performance and learning and memory. In this study, we examined Long-Evans hooded male rats maintained on a standard diet (20.5 ppm F-) or a low F- diet (3.24 ppm F-) with drinking water exposure to 0, 10, or 20 ppm F- from gestational day 6 through adulthood. At postnatal day 25, brain F- levels were 0.048 or 0.081 μg/g and femur 235 or 379.8 μg/g for 10 and 20 ppm F-, respectively. Levels increase with age and in adults, levels for plasma were 0.036 or 0.025 μg/ml; for the brain 0.266 or 0.850 μg/g; and for the femur, 681.2 or 993.4 μg/g. At these exposure levels, we observed no exposure-related differences in motor, sensory, or learning and memory performance on running wheel, open-field activity, light/dark place preference, elevated plus maze, pre-pulse startle inhibition, passive avoidance, hot-plate latency, Morris water maze acquisition, probe test, reversal learning, and Y-maze. Serum triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) levels were not altered as a function of 10 or 20 ppm F- in the drinking water. No exposure-related pathology was observed in the heart, liver, kidney, testes, seminal vesicles, or epididymides. Mild inflammation in the prostate gland was observed at 20 ppm F-. No evidence of neuronal death or glial activation was observed in the hippocampus at 20 ppm F-.
Collapse
Affiliation(s)
- Christopher A McPherson
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Mail Drop C1-04, P.O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Guozhu Zhang
- Social & Scientific Systems, Inc, Durham, NC, 27703, USA
| | - Richard Gilliam
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Mail Drop C1-04, P.O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Sukhdev S Brar
- Cellular & Molecular Pathology Branch, Division of the National Toxicology Program, NIEHS, Research Tringle Park, NC, 27709, USA
| | - Ralph Wilson
- Cellular & Molecular Pathology Branch, Division of the National Toxicology Program, NIEHS, Research Tringle Park, NC, 27709, USA
| | - Amy Brix
- Experimental Pathology Laboratories, Research Triangle Park, NC, USA
| | | | - G Jean Harry
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Mail Drop C1-04, P.O. Box 12233, Research Triangle Park, NC, 27709, USA.
| |
Collapse
|
17
|
Goulding DR, White SS, McBride SJ, Fenton SE, Harry GJ. Gestational exposure to perfluorooctanoic acid (PFOA): Alterations in motor related behaviors. Neurotoxicology 2017; 58:110-119. [PMID: 27888120 PMCID: PMC5345697 DOI: 10.1016/j.neuro.2016.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/18/2016] [Accepted: 11/21/2016] [Indexed: 10/20/2022]
Abstract
Perfluoroalkyl and polyfluoroalkyl substances are used in commercial applications and developmental exposure has been implicated in alterations in neurobehavioral functioning. While associations between developmental perfluorooctanoic acid (PFOA) exposure and human outcomes have been inconsistent, studies in experimental animals suggest alterations in motor related behaviors. To examine a dose-response pattern of neurobehavioral effects following gestational exposure to PFOA, pregnant CD-1 mice received PFOA (0, 0.1, 0.3, 1.0mg/kg/day) via oral gavage from gestational day 1-17 and the male offspring examined. Motor activity assessments on postnatal day (PND)18, 19, and 20 indicated a shift in the developmental pattern with an elevated activity level observed in the 1.0mg/kg/day dose group on PND18. In the adult, no alterations were observed in body weights, activity levels, diurnal pattern of running wheel activity, startle response, or pre-pulse startle inhibition. In response to a subcutaneous injection of saline or nicotine (80μg/kg), all animals displayed a transient increase in activity likely associated with handling with no differences observed across dose groups. Inhibition of motor activity over 18days of 400μg/kg nicotine injection was not significantly different across dose groups. Hyperactivity induced by 2mg/kg (+)-methamphetamine hydrochloride intraperitoneal injection was significantly lower in the 1.0mg/kg/day PFOA dose group as compared to controls. Taken together, these data suggest that the effects on motor-related behaviors with gestational PFOA exposure do not mimic those reported for acute postnatal exposure. Changes were not observed at dose levels under 1.0mg/kg/day PFOA. Further examination of pathways associated with methamphetamine-induced activity is warranted.
Collapse
Affiliation(s)
- David R Goulding
- Comparative Medicine Branch, Division of Intramural Research; National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, 27709, USA
| | - Sally S White
- Reproductive Endocrinology Group, National Toxicology Program Laboratory (NTPL), Division of the National Toxicology Program (DNTP), NIEHS, USA
| | | | - Suzanne E Fenton
- Reproductive Endocrinology Group, National Toxicology Program Laboratory (NTPL), Division of the National Toxicology Program (DNTP), NIEHS, USA
| | | |
Collapse
|
18
|
Szabo ST, Harry GJ, Hayden KM, Szabo DT, Birnbaum L. Comparison of Metal Levels between Postmortem Brain and Ventricular Fluid in Alzheimer's Disease and Nondemented Elderly Controls. Toxicol Sci 2015; 150:292-300. [PMID: 26721301 DOI: 10.1093/toxsci/kfv325] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
An essential metal hypothesis for neurodegenerative disease suggests an alteration in metal homeostasis contributing to the onset and progression of disease. Similar associations have been proposed for nonessential metals. To examine the relationship between metal levels in brain tissue and ventricular fluid (VF), postmortem samples of frontal cortex (FC) and VF from Alzheimer's disease (AD) cases and nondemented elderly subjects were analyzed for arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), nickel (Ni), tin (Sn), vanadium (V), and zinc (Zn) using inductively coupled plasma sector field mass spectrometry. All metals, with exception of equivalent Pb levels, were lower in the VF, compared to FC. Within-subject comparisons demonstrated that VF levels were not representative of levels within brain tissue. The essential metals Cu, Fe, and Zn were found highest in both compartments. Cd, Hg, and V levels in the VF were below the limit of quantification. In AD cases, FC levels of Fe were higher and As and Cd were lower than levels in controls, while levels of As in the VF were higher. Parameter estimates for FC metal levels indicated an association of Braak stage and higher Fe levels and an association of Braak stage and lower As, Mn, and Zn levels. The data showed no evidence of an accumulation of nonessential metals within the AD brain and, with the exception of As, showed no significant shift in the ratio of FC to VF levels to indicate differential clearance.
Collapse
Affiliation(s)
- Steven T Szabo
- *Veterans Affairs Medical Center, Mental Health Service Line, Durham, North Carolina 27705; Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina 27705;
| | - G Jean Harry
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Kathleen M Hayden
- Department of Psychiatry and Behavioral Sciences, Joseph and Kathleen ADRC, Duke University Medical Center, Durham, North Carolina 27705
| | - David T Szabo
- RAI Services Company, Winston Salem, North Carolina 27102; and
| | - Linda Birnbaum
- National Cancer Institute, National Institutes of Health (NIH), Research Triangle Park, North Carolina 27709
| |
Collapse
|
19
|
Basselin M, Ramadan E, Igarashi M, Chang L, Chen M, Kraft AD, Harry GJ, Rapoport SI. Imaging upregulated brain arachidonic acid metabolism in HIV-1 transgenic rats. J Cereb Blood Flow Metab 2015; 35:1386. [PMID: 26228569 PMCID: PMC4527996 DOI: 10.1038/jcbfm.2015.122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This article has been retracted by the Editors in Chief at the request of the author Stanley I Rapoport following the finding of the National Institutes of Health that Dr Mireille Basselin engaged in research misconduct by fabricating data in Figure 4A–C and Figure 5B. None of the other authors are implicated in any way.
Collapse
|
20
|
Awada R, Saulnier-Blache JS, Grès S, Bourdon E, Rondeau P, Parimisetty A, Orihuela R, Harry GJ, d'Hellencourt CL. Autotaxin downregulates LPS-induced microglia activation and pro-inflammatory cytokines production. J Cell Biochem 2015; 115:2123-32. [PMID: 25053164 DOI: 10.1002/jcb.24889] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 07/18/2014] [Indexed: 01/28/2023]
Abstract
Inflammation is essential in defense against infection or injury. It is tightly regulated, as over-response can be detrimental, especially in immune-privileged organs such as the central nervous system (CNS). Microglia constitutes the major source of inflammatory factors, but are also involved in the regulation of the inflammation and in the reparation. Autotaxin (ATX), a phospholipase D, converts lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA) and is upregulated in several CNS injuries. LPA, a pleiotropic immunomodulatory factor, can induce multiple cellular processes including morphological changes, proliferation, death, and survival. We investigated ATX effects on microglia inflammatory response to lipopolysaccharide (LPS), mimicking gram-negative infection. Murine BV-2 microglia and stable transfected, overexpressing ATX-BV-2 (A +) microglia were treated with LPS. Tumor necrosis factor α (TNFα), interleukin (IL)-6, and IL-10 mRNA and proteins levels were examined by qRT-PCR and ELISA, respectively. Secreted LPA was quantified by a radioenzymatic assay and microglial activation markers (CD11b, CD14, B7.1, and B7.2) were determined by flow cytometry. ATX expression and LPA production were significantly enhanced in LPS treated BV-2 cells. LPS induction of mRNA and protein level for TNFα and IL-6 were inhibited in A+ cells, while IL-10 was increased. CD11b, CD14, and B7.1, and B7.2 expressions were reduced in A+ cells. Our results strongly suggest deactivation of microglia and an IL-10 inhibitory of ATX with LPS induced microglia activation.
Collapse
Affiliation(s)
- Rana Awada
- Groupe d'Etude sur l'Inflammation Chronique et l'Obésité (GEICO) EA 4516, Université de La Réunion, 15 avenue R. Cassin, CS 92003, 97715, Saint Denis Cedex and Plateforme CYROI, 2 Rue Maxime Rivière, BP 80 005, Sainte Clotilde Cedex, Reunion Island, France
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
McPherson CA, Merrick BA, Harry GJ. In vivo molecular markers for pro-inflammatory cytokine M1 stage and resident microglia in trimethyltin-induced hippocampal injury. Neurotox Res 2013; 25:45-56. [PMID: 24002884 DOI: 10.1007/s12640-013-9422-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 08/13/2013] [Accepted: 08/20/2013] [Indexed: 12/18/2022]
Abstract
Microglia polarization to the classical M1 activation state is characterized by elevated pro-inflammatory cytokines; however, a full profile has not been generated in the early stages of a sterile inflammatory response recruiting only resident microglia. We characterized the initial M1 state in a hippocampal injury model dependent upon tumor necrosis factor (TNF) receptor signaling for dentate granule cell death. Twenty-one-day-old CD1 male mice were injected with trimethyltin (TMT 2.3 mg/kg, i.p.) and the hippocampus was examined at an early stage (24-h post-dosing) of neuronal death. Glia activation was assessed using a custom quantitative nuclease protection assay. We report elevated mRNA levels for glia response such as ionizing calcium-binding adapter molecule-1 and glial fibrillary acidic protein (Gfap); Fas, hypoxia inducible factor alpha, complement component 1qb, TNF-related genes (Tnf, Tnfaip3, Tnfrsfla); interleukin-1 alpha, Cd44, chemokine (C-C motif) ligand (Ccl)2, Cc14, integrin alpha M, lipocalin (Lcn2), and secreted phosphoprotein 1 (Spp1). These changes occurred in the absence of changes in matrix metalloproteinase 9 and 12, neural cell adhesion molecule, metabotropic glutamate receptor (Grm)3, and Ly6/neurotoxin 1 (Lynx1), as well as, a decrease in neurotrophin 3, glutamate receptor subunit epsilon (Grin)-2b, and neurotrophic tyrosine kinase receptor, type 3. The M2 anti-inflammatory marker, transforming growth factor beta-1 (Tgfb1) was elevated. mRNAs associated with early stage of injury-induced neurogenesis including fibroblast growth factor 21 and Mki67 were elevated. In the "non-injured" temporal cortex receiving projections from the hippocampus, Lynx1, Grm3, and Grin2b were decreased and Gfap increased. Formalin fixed-paraffin-embedded tissue did not generate a comparable profile.
Collapse
Affiliation(s)
- C A McPherson
- Neurotoxicology Group, Division of National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, P.O. Box 12233, MD E1-07, Research Triangle Park, NC, 27709, USA
| | | | | |
Collapse
|
22
|
Abstract
Microglia are critical nervous system-specific cells influencing brain development, maintenance of the neural environment, response to injury, and repair. They contribute to neuronal proliferation and differentiation, pruning of dying neurons, synaptic remodeling and clearance of debris and aberrant proteins. Colonization of the brain occurs during gestation with an expansion following birth with localization stimulated by programmed neuronal death, synaptic pruning, and axonal degeneration. Changes in microglia phenotype relate to cellular processes including specific neurotransmitter, pattern recognition, or immune-related receptor activation. Upon activation, microglia cells have the capacity to release a number of substances, e.g., cytokines, chemokines, nitric oxide, and reactive oxygen species, which could be detrimental or beneficial to the surrounding cells. With aging, microglia shift their morphology and may display diminished capacity for normal functions related to migration, clearance, and the ability to shift from a pro-inflammatory to an anti-inflammatory state to regulate injury and repair. This shift in microglia potentially contributes to increased susceptibility and neurodegeneration as a function of age. In the current review, information is provided on the colonization of the brain by microglia, the expression of various pattern recognition receptors to regulate migration and phagocytosis, and the shift in related functions that occur in normal aging.
Collapse
Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, MD C1-04, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
23
|
Muessel MJ, Harry GJ, Armstrong DL, Storey NM. SDF-1α and LPA modulate microglia potassium channels through rho gtpases to regulate cell morphology. Glia 2013; 61:1620-8. [PMID: 23893870 DOI: 10.1002/glia.22543] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 05/14/2013] [Accepted: 05/16/2013] [Indexed: 12/11/2022]
Abstract
Microglia are the resident immune cells of the brain, which are important therapeutic targets for regulating the inflammatory responses particularly neurodegeneration in the aging human brain. The activation, chemotaxis and migration of microglia are regulated through G-protein coupled receptors by chemokines such as stromal cell-derived factor (SDF)-1α and bioactive lysophospholipids such as lysophosphatidic acid (LPA). Potassium channels play important roles in microglial function and cell fate decisions; however, the regulation of microglial potassium channels has not been fully elucidated. Here we show reciprocal action of SDF-1α and LPA, on potassium currents through Kir2.1 channels in primary murine microglia. The potassium channel modulation is mediated by the same small GTPases, Rac and Rho that regulate the actin cytoskeleton. SDF-1α rapidly increased the Kir2.1 current amplitude and cell spreading. These effects were mimicked by dialysing the cells with constitutively active Rac1 protein, and they were blocked by inhibiting the phosphatidylinositol 3-kinase (PI3K) with wortmannin. In contrast, LPA and constitutively active RhoA decreased the Kir2.1 currents and stimulated cell contraction. Thus, SDF-1α and LPA regulate both the actin cytoskeleton and the Kir2.1 potassium channels through the same Rho GTPase signaling pathways. The inhibition of Kir2.1 with chloroethylclonidine produced cell contraction independently of chemokine action. This suggests that potassium channels are essential for the morphological phenotype and functioning of microglia. In conclusion, the small GTPases, Rac and Rho, modulate Kir2.1 channels and block of Kir2.1 channels causes changes in microglia morphology.
Collapse
Affiliation(s)
- Michelle J Muessel
- Laboratory of Neurobiology, NIEHS/NIH, Research Triangle Park, North Carolina, USA
| | | | | | | |
Collapse
|
24
|
Brunssen SH, Moy SS, Toews AD, McPherson CA, Harry GJ. Interleukin-6 (IL-6) receptor/IL-6 fusion protein (Hyper IL-6) effects on the neonatal mouse brain: possible role for IL-6 trans-signaling in brain development and functional neurobehavioral outcomes. Brain Behav Immun 2013; 27:42-53. [PMID: 22985907 PMCID: PMC3565379 DOI: 10.1016/j.bbi.2012.08.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 08/17/2012] [Accepted: 08/30/2012] [Indexed: 12/30/2022] Open
Abstract
Adverse neurodevelopmental outcomes are linked to perinatal production of inflammatory mediators, including interleukin 6 (IL-6). While a pivotal role for maternal elevation in IL-6 has been established in determining neurobehavioral outcomes in the offspring and considered the primary target mediating the fetal inflammatory response, questions remain as to the specific actions of IL-6 on the developing brain. CD-1 male mice received a subdural injection of the bioactive fusion protein, hyper IL-6 (HIL-6) on postnatal-day (PND)4 and assessed from preweaning until adulthood. Immunohistochemical evaluation of astrocytes and microglia and mRNA levels for pro-inflammatory cytokines and host response genes indicated no evidence of an acute neuroinflammatory injury response. HIL-6 accelerated motor development and increased reactivity to stimulation and number of entries in a light/dark chamber, decreased ability to learn to withhold a response in passive avoidance, and effected deficits in social novelty behavior. No changes were observed in motor activity, pre-pulse startle inhibition, or learning and memory in the Morris water maze or radial arm maze, as have been reported for models of more severe developmental neuroinflammation. In young animals, mRNA levels for MBP and PLP/DM20 decreased and less complexity of MBP processes in the cortex was evident by immunohistochemistry. The non-hydroxy cerebroside fraction of cerebral lipids was increased. These results provide evidence for selective effects of IL-6 signaling, particularly trans-signaling, in the developing brain in the absence of a general neuroinflammatory response. These data contribute to our further understanding of the multiple aspects of IL-6 signaling in the developing brain.
Collapse
Affiliation(s)
- Susan H. Brunssen
- School of Nursing, University of North Carolina, North Carolina,Carolina Institute for Developmental Disabilities, University of North Carolina, North Carolina,National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC
| | - Sheryl S. Moy
- Carolina Institute for Developmental Disabilities, University of North Carolina, North Carolina
| | - Arrel D. Toews
- Department of Cellular and Molecular Biology, University of North Carolina, North Carolina
| | - Christopher A. McPherson
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC
| | - G. Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC,Corresponding author: G. Jean Harry, Ph.D.; NIEHS, P.O. Box 12233, MD C1-04; Research Triangle Park, NC, 27709 [1 919 541-0927][]
| |
Collapse
|
25
|
Harry GJ. Neuroinflammation: a need to understand microglia as resident cells of the developing brain. Neurotoxicology 2012; 33:558-9. [PMID: 22507950 DOI: 10.1016/j.neuro.2012.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 03/30/2012] [Indexed: 12/20/2022]
Abstract
Neuroinflammation and microglia as the resident immune cells of the brain has garnered a significant amount of interest with regards to brain injury and neurotoxicology. Much of this interest and research has been focused on responses in the adult brain with little attention paid to the role of these cells during development. The available data suggests that one must view microglia and their processes during development somewhat differently. In addition, modification to microglia during development may lay a framework for subtle to significant changes in the susceptibility of the mature brain to secondary insults. A number of these point are now being raised for consideration.
Collapse
Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, PO Box 12233, MD C1-04, Research Triangle Park, NC 27709, USA.
| |
Collapse
|
26
|
Bhattacharjee AK, White L, Chang L, Ma K, Harry GJ, Deutsch J, Rapoport SI. Bilateral common carotid artery ligation transiently changes brain lipid metabolism in rats. Neurochem Res 2012; 37:1490-8. [PMID: 22422289 DOI: 10.1007/s11064-012-0740-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 01/04/2012] [Accepted: 02/20/2012] [Indexed: 10/28/2022]
Abstract
Brain lipid metabolism was studied in rats following permanent bilateral common carotid artery ligation (BCCL), a model for chronic cerebral hypoperfusion. Unesterified (free) fatty acids (uFA) and acyl-CoA concentrations were measured 6 h, 24 h, and 7 days after BCCL or sham surgery, in high energy-microwaved brain. In BCCL compared to sham rats, cytosolic phospholipase A(2) (cPLA(2)) immunoreactivity in piriform cortex, and concentrations of total uFA and arachidonoyl-CoA, an intermediate for arachidonic acid reincorporation into phospholipids, were increased only at 6 h. At 24 h, immunoreactivity for secretory phospholipase A(2) (sPLA(2)), which may regulate blood flow, was increased near cortical and hippocampal blood vessels. BCCL did not affect levels of brain IB(4)+ microglia, glial fibrillary acidic protein (GFAP)+ astrocytes, cyclooxygenase-2 (COX-2) immunoreactivity at any time, but increased cPLA(2) immunoreactivity in one region at 6 h. Thus, BCCL affected brain lipid metabolism transiently, likely because of compensatory sPLA(2)-mediated vasodilation, without producing evidence of neuroinflammation.
Collapse
Affiliation(s)
- Abesh Kumar Bhattacharjee
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
Harry GJ, Kraft AD. Microglia in the developing brain: a potential target with lifetime effects. Neurotoxicology 2012; 33:191-206. [PMID: 22322212 DOI: 10.1016/j.neuro.2012.01.012] [Citation(s) in RCA: 179] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/24/2012] [Accepted: 01/25/2012] [Indexed: 12/15/2022]
Abstract
Microglia are a heterogenous group of monocyte-derived cells serving multiple roles within the brain, many of which are associated with immune and macrophage like properties. These cells are known to serve a critical role during brain injury and to maintain homeostasis; yet, their defined roles during development have yet to be elucidated. Microglial actions appear to influence events associated with neuronal proliferation and differentiation during development, as well as, contribute to processes associated with the removal of dying neurons or cellular debris and management of synaptic connections. These long-lived cells display changes during injury and with aging that are critical to the maintenance of the neuronal environment over the lifespan of the organism. These processes may be altered by changes in the colonization of the brain or by inflammatory events during development. This review addresses the role of microglia during brain development, both structurally and functionally, as well as the inherent vulnerability of the developing nervous system. A framework is presented considering microglia as a critical nervous system-specific cell that can influence multiple aspects of brain development (e.g., vascularization, synaptogenesis, and myelination) and have a long term impact on the functional vulnerability of the nervous system to a subsequent insult, whether environmental, physical, age-related, or disease-related.
Collapse
Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
| | | |
Collapse
|
28
|
Funk JA, Gohlke J, Kraft AD, McPherson CA, Collins JB, Harry GJ. Voluntary exercise protects hippocampal neurons from trimethyltin injury: possible role of interleukin-6 to modulate tumor necrosis factor receptor-mediated neurotoxicity. Brain Behav Immun 2011; 25:1063-77. [PMID: 21435392 PMCID: PMC3138904 DOI: 10.1016/j.bbi.2011.03.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 03/16/2011] [Accepted: 03/16/2011] [Indexed: 01/02/2023] Open
Abstract
In the periphery, exercise induces interleukin (IL)-6 to downregulate tumor necrosis factor (TNF), elevate interleukin-1 receptor antagonist (IL-1RA), decreasing inflammation. Exercise also offers neuroprotection and facilitates brain repair. IL-6 production in the hippocampus following exercise suggests the potential of a similar protective role as in the periphery to down-regulate TNFα and inflammation. Using a chemical-induced model of hippocampal dentate granule cell death (trimethyltin, TMT 2.4 mg/kg, ip) dependent upon TNF receptor signaling, we demonstrate neuroprotection in mice with 2 weeks access to running wheel. Exercise attenuated neuronal death and diminished elevations in TNFα, TNF receptor 1, myeloid differentiation primary response gene (MyD) 88, transforming growth factor β, chemokine (C-C motif) ligand 2 (CCL2), and CCL3. Elevated mRNA levels for IL-1α, IL-1RA, occurred with injury and protection. mRNA and protein levels of IL-6 and neuronal expression of IL-6 receptor α, were elevated with injury and protection. Microarray pathway analysis supported an up-regulation of TNFα cell death signaling pathways with TMT and inhibition by exercise. IL-6 pathway recruitment occurred in both conditions. IL-6 downstream signal events differed in the level of STAT3 activation. Exercise did not increase mRNA levels of brain derived neurotrophic factor, nerve growth factor, or glial derived neurotrophic factor. In IL-6 deficient mice, exercise did not attenuate TMT-induced tremor and a diminished level of neuroprotection was observed. These data suggest a contributory role for IL-6 induced by exercise for neuroprotection in the CNS similar to that seen in the periphery.
Collapse
Affiliation(s)
- Jason A. Funk
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
| | - Julia Gohlke
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC,Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, AL
| | - Andrew D. Kraft
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
| | - Christopher A. McPherson
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
| | - Jennifer B. Collins
- Division of Extramural Research and Training, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
| | - G. Jean Harry
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC,corresponding author: G. Jean Harry, National Institute of Environmental Health Sciences, P.O. Box 12233, MD C1-04, Research Triangle Park, NC 27709. Ph. (919) 541-0927, Fax. (919) 541-4634,
| |
Collapse
|
29
|
McPherson CA, Aoyama M, Harry GJ. Interleukin (IL)-1 and IL-6 regulation of neural progenitor cell proliferation with hippocampal injury: differential regulatory pathways in the subgranular zone (SGZ) of the adolescent and mature mouse brain. Brain Behav Immun 2011; 25:850-62. [PMID: 20833246 PMCID: PMC3033445 DOI: 10.1016/j.bbi.2010.09.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 09/03/2010] [Accepted: 09/06/2010] [Indexed: 12/13/2022] Open
Abstract
Current data suggests an association between elevations in interleukin 1 (IL-1)α, IL-1β, and IL-6 and the proliferation of neural progenitor cells (NPCs) following brain injury. A limited amount of work implicates changes in these pro-inflammatory responses with diminished NPC proliferation observed as a function of aging. In the current study, adolescent (21day-old) and 1year-old CD-1 male mice were injected with trimethyltin (TMT, 2.3mg/kg, i.p.) to produce acute apoptosis of hippocampal dentate granule cells. In this model, fewer 5-bromo-2'-deoxyuridine (BrdU)+ NPC were observed in both naive and injured adult hippocampus as compared to the corresponding number seen in adolescent mice. At 48h post-TMT, a similar level of neuronal death was observed across ages, yet activated ameboid microglia were observed in the adolescent and hypertrophic process-bearing microglia in the adult. IL-1α mRNA levels were elevated in the adolescent hippocampus; IL-6 mRNA levels were elevated in the adult. In subgranular zone (SGZ) isolated by laser-capture microdissection, IL-1β was detected but not elevated by TMT, IL-1a was elevated at both ages, while IL-6 was elevated only in the adult. Naïve NPCs isolated from the hippocampus expressed transcripts for IL-1R1, IL-6Rα, and gp130 with significantly higher levels of IL-6Rα mRNA in the adult. In vitro, IL-1α (150pg/ml) stimulated proliferation of adolescent NPCs; IL-6 (10ng/ml) inhibited proliferation of adolescent and adult NPCs. Microarray analysis of SGZ post-TMT indicated a prominence of IL-1a/IL-1R1 signaling in the adolescent and IL-6/gp130 signaling in the adult.
Collapse
Affiliation(s)
- CA McPherson
- Neurotoxicology Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health
,Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - M Aoyama
- Neurotoxicology Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health
,Department of Molecular Neurobiology, Nagoya City University, Nagoya, Japan
| | - GJ Harry
- Neurotoxicology Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health
,
Corresponding address: National Institute of Environmental Health Sciences, P.O. Box 12233, MD C1-04, Research Triangle Park, NC 27709. Ph. (919) 541-0927, Fax. (919) 541-4634,
| |
Collapse
|
30
|
Kraft AD, Kaltenbach LS, Lo DC, Harry GJ. Activated microglia proliferate at neurites of mutant huntingtin-expressing neurons. Neurobiol Aging 2011; 33:621.e17-33. [PMID: 21482444 DOI: 10.1016/j.neurobiolaging.2011.02.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 02/01/2011] [Accepted: 02/16/2011] [Indexed: 01/13/2023]
Abstract
In Huntington's disease (HD), mutated huntingtin (mhtt) causes striatal neurodegeneration which is paralleled by elevated microglia cell numbers. In vitro corticostriatal slice and primary neuronal culture models, in which neuronal expression of mhtt fragments drives HD-like neurotoxicity, were employed to examine wild type microglia during both the initiation and progression of neuronal pathology. As neuronal pathology progressed, microglia initially localized in the vicinity of neurons expressing mhtt fragments increased in number, demonstrated morphological evidence of activation, and expressed the proliferation marker, Ki67. These microglia were positioned along irregular neurites, but did not localize with mhtt inclusions nor exacerbate mhtt fragment-induced neurotoxicity. Prior to neuronal pathology, microglia upregulated ionized calcium binding adaptor molecule 1 (Iba1), signaling a functional shift. With neurodegeneration, interleukin-6 and complement component 1q were increased. The results suggest a stimulatory, proliferative signal for microglia present at the onset of mhtt fragment-induced neurodegeneration. Thus, microglia effect a localized inflammatory response to neuronal mhtt expression that may serve to direct microglial removal of dysfunctional neurites or aberrant synapses, as is required for reparative actions in vivo.
Collapse
Affiliation(s)
- Andrew D Kraft
- Neurotoxicology Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | | | | |
Collapse
|
31
|
Ravanan P, Harry GJ, Awada R, Hoareau L, Tallet F, Roche R, d’Hellencourt CL. Exposure to an organometal compound stimulates adipokine and cytokine expression in white adipose tissue. Cytokine 2011; 53:355-62. [PMID: 21194965 PMCID: PMC3418814 DOI: 10.1016/j.cyto.2010.11.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2009] [Revised: 08/13/2010] [Accepted: 11/19/2010] [Indexed: 12/25/2022]
Abstract
OBJECTIVE White adipose tissue (WAT) is now considered a defined tissue capable of interactions with other organ systems. WAT role in elevating the level of systemic chronic inflammation suggests that alterations in this tissue as the result of disease or environmental factors may influence the development and progression of various obesity-related pathologies. This study investigated WAT cell-specific responses to an organometal compound, trimethyltin (TMT), to determine possible contribution to induced inflammation. METHODS Human primary mature adipocytes and macrophage differentiated THP-1 cells were cultured in TMT presence and relative toxicities and different adipokine levels were determined. The inflammatory response was examined in TMT presence for primary cells from obese ob/ob mice WAT, and after TMT injection in ob/ob mice. RESULTS Both adipocytes and macrophages were resistant to cell death induced by TMT. However, adipocytes cultured in TMT presence showed increased expression of TNFα and IL-6, and modified leptin levels. In macrophage cultures, TMT also increased TNFα and IL-6, while MCP-1 and MIP-1α were decreased. In vivo, a single injection of TMT in ob/ob mice, elevated TNFα, MIP-1α and adiponectin in WAT. CONCLUSIONS Elevation of the inflammatory related products can be induced by chemical exposure in adipocytes and macrophages, as well as murine WAT. These data suggest that numerous factors, including a systemic chemical exposure, can induce an inflammatory response from the WAT. Furthermore, when characterizing both chemical-induced toxicity and the progression of the chronic inflammation associated with elevated WAT content, such responses in this target tissue should be taken into consideration.
Collapse
Affiliation(s)
- Palaniyandi Ravanan
- Laboratoire de Biochimie et de Génétique Moléculaire, Groupe d’Etude de l’Inflammation Chronique et de l’Obésité (GEICO), Université de La Réunion, Faculté des Sciences, 15 avenue R. Cassin and Plateforme CYROI, 2 rue Maxime Rivière, 97490 Sainte Clotilde, France
| | - G. Jean Harry
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC, USA
| | - Rana Awada
- Laboratoire de Biochimie et de Génétique Moléculaire, Groupe d’Etude de l’Inflammation Chronique et de l’Obésité (GEICO), Université de La Réunion, Faculté des Sciences, 15 avenue R. Cassin and Plateforme CYROI, 2 rue Maxime Rivière, 97490 Sainte Clotilde, France
| | - Laurence Hoareau
- Laboratoire de Biochimie et de Génétique Moléculaire, Groupe d’Etude de l’Inflammation Chronique et de l’Obésité (GEICO), Université de La Réunion, Faculté des Sciences, 15 avenue R. Cassin and Plateforme CYROI, 2 rue Maxime Rivière, 97490 Sainte Clotilde, France
| | - Frank Tallet
- Laboratoire de Biochimie UF4130, Centre Hospitalier Régional Félix Guyon, La Réunion, France
| | - Régis Roche
- Laboratoire de Biochimie et de Génétique Moléculaire, Groupe d’Etude de l’Inflammation Chronique et de l’Obésité (GEICO), Université de La Réunion, Faculté des Sciences, 15 avenue R. Cassin and Plateforme CYROI, 2 rue Maxime Rivière, 97490 Sainte Clotilde, France
| | - Christian Lefebvre d’Hellencourt
- Laboratoire de Biochimie et de Génétique Moléculaire, Groupe d’Etude de l’Inflammation Chronique et de l’Obésité (GEICO), Université de La Réunion, Faculté des Sciences, 15 avenue R. Cassin and Plateforme CYROI, 2 rue Maxime Rivière, 97490 Sainte Clotilde, France
| |
Collapse
|
32
|
Basselin M, Ramadan E, Igarashi M, Chang L, Chen M, Kraft AD, Harry GJ, Rapoport SI. Imaging upregulated brain arachidonic acid metabolism in HIV-1 transgenic rats. J Cereb Blood Flow Metab 2011; 31:486-93. [PMID: 20664612 PMCID: PMC2992106 DOI: 10.1038/jcbfm.2010.111] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Human immunodeficiency virus (HIV)-associated infection involves the entry of virus-bearing monocytes into the brain, followed by microglial activation, neuroinflammation, and upregulated arachidonic acid (AA) metabolism. The HIV-1 transgenic (Tg) rat, a noninfectious HIV-1 model, shows neurologic and behavioral abnormalities after 5 months of age. We hypothesized that brain AA metabolism would be elevated in older HIV-1 Tg rats in vivo. Arachidonic acid incorporation from the plasma into the brain of unanesthetized 7-to-9-month-old rats was imaged using quantitative autoradiography, after [1-(14)C]AA infusion. Brain phospholipase (PLA(2)) activities and eicosanoid concentrations were measured, and enzymes were localized by immunostaining. AA incorporation coefficients k* and rates J(in), measures of AA metabolism, were significantly higher in 69 of 81 brain regions in HIV-1 Tg than in control rats, as were activities of cytosolic (c)PLA(2)-IV, secretory (s)PLA(2), and calcium independent (i)PLA(2)-VI, as well as prostaglandin E(2) and leukotriene B(4) concentrations. Immunostaining of somatosensory cortex showed elevated cPLA(2)-IV, sPLA(2)-IIA, and cyclooxygenase-2 in neurons. Brain AA incorporation and other markers of AA metabolism are upregulated in HIV-1 Tg rats, in which neurologic changes and neuroinflammation have been reported. Positron emission tomography with [1-(11)C]AA could be used to test whether brain AA metabolism is upregulated in HIV-1-infected patients, in relation to cognitive and behavioral disturbances.
Collapse
Affiliation(s)
- Mireille Basselin
- Brain Physiology and Metabolism Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
McPherson CA, Kraft AD, Harry GJ. Injury-induced neurogenesis: consideration of resident microglia as supportive of neural progenitor cells. Neurotox Res 2010; 19:341-52. [PMID: 20524106 DOI: 10.1007/s12640-010-9199-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 04/29/2010] [Accepted: 05/03/2010] [Indexed: 01/26/2023]
Abstract
The induction of neurogenesis in the adult subgranular zone (SGZ) by injury is often accompanied by changes in the extracellular environment that can have significant impacts on neural progenitor cells (NPCs). We examined the induction of neurogenesis in the SGZ at 72 h following an injection of the hippocampal toxicant, trimethyltin (TMT; 2 mg/kg, ip) inducing apoptosis in dentate granule neurons. BrdU+ incorporation during the active period of neuronal death indicated NPC proliferation and migration of newly generated cells into the granule cell layer (GCL). BrdU+ cells were transiently in contact with process bearing microglia within the inner SGZ layer. Contact with GFAP+ astrocyte processes occurred once cells were within the GCL. A small percentage of the BrdU+ cells within the SGZ region showed immunoreactivity for tumor necrosis factor (TNF) p75 receptor (TNFp75R). In mice deficient for TNFp75R, TMT injection produced an equivalent level of dentate granule cell death however; BrdU+ cells were localized at the SGZ as compared to the presence of cells within the GCL in the WT mice dosed with TMT. These data suggest that cells generated by NPCs in the SGZ induced with a focal lesion to the dentate granule neurons of adolescent mice maintain the capacity to utilize the neuroinflammation and microglia responses within their environment for migration into the GCL.
Collapse
Affiliation(s)
- Christopher A McPherson
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Science, National Institutes of Health, MD C1-04, P.O. Box 12233, Research Triangle Park, NC 27709, USA
| | | | | |
Collapse
|
34
|
Dosunmu R, Wu J, Adwan L, Maloney B, Basha MR, McPherson CA, Harry GJ, Rice DC, Zawia NH, Lahiri DK. Lifespan profiles of Alzheimer's disease-associated genes and products in monkeys and mice. J Alzheimers Dis 2010; 18:211-30. [PMID: 19584442 DOI: 10.3233/jad-2009-1138] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is characterized by plaques of amyloid-beta (Abeta) peptide, cleaved from amyloid-beta protein precursor (AbetaPP). Our hypothesis is that lifespan profiles of AD-associated mRNA and protein levels in monkeys would differ from mice and that differential lifespan expression profiles would be useful to understand human AD pathogenesis. We compared profiles of AbetaPP mRNA, AbetaPP protein, and Abeta levels in rodents and primates. We also tracked a transcriptional regulator of the AbetaPP gene, specificity protein 1 (SP1), and the beta amyloid precursor cleaving enzyme (BACE1). In mice, AbetaPP and SP1 mRNA and their protein products were elevated late in life; Abeta levels declined in old age. In monkeys, SP1, AbetaPP, and BACE1 mRNA declined in old age, while protein products and Abeta levels rose. Proteolytic processing in both species did not match production of Abeta. In primates, AbetaPP and SP1 mRNA levels coordinate, but an inverse relationship exists with corresponding protein products as well as Abeta levels. Comparison of human DNA and mRNA sequences to monkey and mouse counterparts revealed structural features that may explain differences in transcriptional and translational processing. These findings are important for selecting appropriate models for AD and other age-related diseases.
Collapse
Affiliation(s)
- Remi Dosunmu
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Kraft AD, McPherson CA, Harry GJ. Heterogeneity of microglia and TNF signaling as determinants for neuronal death or survival. Neurotoxicology 2009; 30:785-93. [PMID: 19596372 DOI: 10.1016/j.neuro.2009.07.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 07/01/2009] [Indexed: 12/30/2022]
Abstract
Microglia do not constitute a single, uniform cell population, but rather comprise cells with varied phenotypes, some which are beneficial and others that may require active regulatory control. Thus, gaining a better understanding of the heterogeneity of resident microglia responses will contribute to any interpretation regarding the impact of any such response in the brain. Microglia are the primary source of the pro-inflammatory cytokine, tumor necrosis factor (TNF) that can initiate various effects through the activation of membrane receptors. The TNF p55 receptor contains a death domain and activation normally leads to cellular apoptosis; however, under specific conditions, receptor activation can also lead to the activation of NF-kappaB and contribute to cell survival. These divergent outcomes have been linked to receptor localization with receptor internalization leading to cell death and membrane localization supporting cell survival. A second TNF receptor, TNF p75 receptor, is normally linked to cell growth and survival, however, it can cooperate with the p55 receptor and contribute to cell death. Thus, while an elevation in TNFalpha in the brain is often considered an indicator of microglia activation and neuroinflammation, a number of factors come into play to determine the final outcome. Data are reviewed demonstrating that heterogeneity in morphological response of microglia and the expression of TNFalpha and TNF receptors are critical in identifying and characterizing neurotoxic events as they relate to neuroinflammation, neuronal damage and in stimulating neuroprotection.
Collapse
Affiliation(s)
- Andrew D Kraft
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC 27709, United States
| | | | | |
Collapse
|
36
|
Wine RN, McPherson CA, Harry GJ. IGF-1 and pAKT signaling promote hippocampal CA1 neuronal survival following injury to dentate granule cells. Neurotox Res 2009; 16:280-92. [PMID: 19526277 DOI: 10.1007/s12640-009-9060-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 04/20/2009] [Accepted: 04/27/2009] [Indexed: 11/26/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) protects neurons from apoptosis and in vivo offers neuroprotective support to hippocampal CA1 pyramidal neurons following ischemia or seizure. IGF-1 signals through IGF-1 receptors activating phosphytidylinositol 3-kinase (PI3K)/Akt or pMAPK pathways. IGF-1 can be induced with injury and microglia and astrocytes may serve as a source of this neurotrophic factor to promote neuronal survival. An acute systemic injection of trimethyltin (TMT; 2 mg/kg, ip) to mice induces apoptosis of dentate granule neurons within 24 h and a differential response of microglia with ramified microglia present in the CA-1 region. Using this model, we studied the role of IGF-1 in the survival of CA-1 pyramidal neurons under conditions of altered synaptic input due to changes in the dentate gyrus. Within 24 h of injection, IGF-1 mRNA levels were elevated in the hippocampus and IGF-1 protein detected in both astrocytes and microglia. IGF-1 was redistributed within the CA-1 neurons corresponding with an increase in cytoplasmic pAkt, elevated PKBalpha/Akt protein levels, and a decrease in the antagonist, Rho. pMAPK was not detected in CA-1 neurons and ERK2 showed a transient decrease followed by a significant increase, suggesting a lack of recruitment of the pMAPK signaling pathway for neuronal survival. In mice deficient for IGF-1, a similar level of apoptosis was observed in dentate granule neurons as compared to wildtype; however, TMT induced a significant level CA-1 neuronal death, further supporting a role for IGF-1 in the survival of CA-1 neurons.
Collapse
Affiliation(s)
- Robert N Wine
- Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, P.O. Box 12233, MD C1-04, Research Triangle Park, NC 27709, USA
| | | | | |
Collapse
|
37
|
Abstract
Membrane rafts are rich in cholesterol and sphingolipids and have specific proteins associated with them. Due to their small size, their identification and isolation have proved to be problematic. Their insolubility in nonionic detergents, such as Triton-X 100, at 4 degrees C has been the most common means of isolation. However, detergent presence can produce artifacts or interfere with ganglioside distribution. The direction is therefore toward the use of detergent-free protocols. We report an optimized method of raft isolation from lipid-rich brain tissue using a detergent-free method. We compared this to Triton-X 100-based isolation along sucrose or Optiprep gradients using the following endpoints: low protein content, high cholesterol content, presence of Flotillin 1 (Flot1), and absence of transferrin receptor (TfR) proteins. These criteria were met in raft fractions isolated in a detergent-free buffer along a sucrose gradient of 5%/35%/42.5%. The use of optiprep gave less consistent results with respect to protein distribution. We demonstrate that clean raft fractions with minimal myelin contamination can be reproducibly obtained in the top three low-density fractions along a sucrose step gradient.
Collapse
Affiliation(s)
- Dixie-Ann Persaud-Sawin
- Laboratory of Molecular Toxicology/Neurotoxicology Group, National Institute of Environmental Health Sciences, RTP, NC 27709, USA.
| | | | | |
Collapse
|
38
|
Harry GJ, Lefebvre d'Hellencourt C, McPherson CA, Funk JA, Aoyama M, Wine RN. Tumor necrosis factor p55 and p75 receptors are involved in chemical-induced apoptosis of dentate granule neurons. J Neurochem 2008; 106:281-98. [PMID: 18373618 DOI: 10.1111/j.1471-4159.2008.05382.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Localized tumor necrosis factor-alpha (TNFalpha) elevation has diverse effects in brain injury often attributed to signaling via TNFp55 or TNFp75 receptors. Both dentate granule cells and CA pyramidal cells express TNF receptors (TNFR) at low levels in a punctate pattern. Using a model to induce selective death of dentate granule cells (trimethyltin; 2 mg/kg, i.p.), neuronal apoptosis [terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ end labeling, active caspase 3 (AC3)] was accompanied by amoeboid microglia and elevated TNFalpha mRNA levels. TNFp55R (55 kDa type-1 TNFR) and TNFp75R (75 kDa type-2 TNFR) immunoreactivity in AC3(+) neurons displayed a pattern suggestive of receptor internalization and a temporal sequence of expression of TNFp55R followed by TNFp75R associated with the progression of apoptosis. A distinct ramified microglia response occurred around CA1 neurons and healthy dentate neurons that displayed an increase in the normal punctate pattern of TNFRs. Neuronal damage was decreased with i.c.v. injection of TNFalpha antibody and in TNFp55R-/-p75R-/- mice that showed higher constitutive mRNA levels for interleukin (IL-1alpha), macrophage inflammatory protein 1-alpha (MIP-1alpha), TNFalpha, transforming growth factor beta1, Fas, and TNFRSF6-assoicated via death domain (FADD). TNFp75R-/- mice showed exacerbated injury and elevated mRNA levels for IL-1alpha, MIP-1alpha, and TNFalpha. In TNFp55R-/- mice, constitutive mRNA levels for TNFalpha, IL-6, caspase 8, FADD, and Fas-associated phosphatase were higher; IL-1alpha, MIP-1alpha, and transforming growth factor beta1 lower. The mice displayed exacerbated neuronal death, delayed microglia response, increased FADD and TNFp75R mRNA levels, and co-expression of TNFp75R in AC3(+) neurons. The data demonstrate TNFR-mediated apoptotic death of dentate granule neurons utilizing both TNFRs and suggest a TNFp75R-mediated apoptosis in the absence of normal TNFp55R activity.
Collapse
MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/immunology
- Apoptosis Regulatory Proteins/drug effects
- Apoptosis Regulatory Proteins/genetics
- Apoptosis Regulatory Proteins/metabolism
- Cytokines/drug effects
- Cytokines/genetics
- Cytokines/metabolism
- Dentate Gyrus/immunology
- Dentate Gyrus/metabolism
- Dentate Gyrus/pathology
- Endocytosis/drug effects
- Endocytosis/physiology
- Fas-Associated Death Domain Protein/drug effects
- Fas-Associated Death Domain Protein/genetics
- Fas-Associated Death Domain Protein/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microglia/drug effects
- Microglia/immunology
- Nerve Degeneration/chemically induced
- Nerve Degeneration/immunology
- Nerve Degeneration/metabolism
- Neurons/drug effects
- Neurons/immunology
- Neurons/metabolism
- Neurotoxins/toxicity
- Receptors, Nerve Growth Factor/drug effects
- Receptors, Nerve Growth Factor/genetics
- Receptors, Nerve Growth Factor/metabolism
- Receptors, Tumor Necrosis Factor/drug effects
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/metabolism
- Receptors, Tumor Necrosis Factor, Type I/drug effects
- Receptors, Tumor Necrosis Factor, Type I/genetics
- Receptors, Tumor Necrosis Factor, Type I/metabolism
- Trimethyltin Compounds/toxicity
Collapse
Affiliation(s)
- G Jean Harry
- Department of Health and Human Services, Neurotoxicology Group, Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
| | | | | | | | | | | |
Collapse
|
39
|
Berman RF, Pessah IN, Mouton PR, Mav D, Harry GJ. Modeling Neonatal Thimerosal Exposure in Mice. Toxicol Sci 2008. [DOI: 10.1093/toxsci/kfn051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
40
|
Zhang D, Harry GJ, Blackshear PJ, Zeldin DC. G-protein pathway suppressor 2 (GPS2) interacts with the regulatory factor X4 variant 3 (RFX4_v3) and functions as a transcriptional co-activator. J Biol Chem 2008; 283:8580-90. [PMID: 18218630 PMCID: PMC2365754 DOI: 10.1074/jbc.m708209200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 01/22/2008] [Indexed: 11/06/2022] Open
Abstract
RFX4_v3 (regulatory factor X4 variant 3) is a brain-specific isoform of the transcription factor RFX4. Insertional mutagenesis in mice demonstrates that Rfx4_v3 is crucial for normal brain development. Many genes involved in critical processes during brain morphogenesis are dysregulated in Rfx4_v3 mutant brains. For example, Cx3cl1 is a CX3C-type chemokine that is abundant in brain and is a direct transcriptional target of RFX4_v3 through a specific promoter X-box (X-box 1), the responsive element for RFX proteins. To identify potential interacting partners for RFX4_v3, we performed yeast two-hybrid analysis. Nine candidate interactors were identified, including GPS2 (G-protein pathway suppressor 2). Indirect immunofluorescence demonstrated that GPS2 and RFX4_v3 co-localized to the nucleus. Both GPS2 and RFX4_v3 mRNAs were also present in most portions of the adult mouse brain as well as in brains at different ages, suggesting that the two proteins could bind to each other. Co-immunoprecipitation assays indicated that physical interactions between GPS2 and RFX4_v3 did indeed occur. Furthermore, GPS2 was recruited to the Cx3cl1 promoter by RFX4_v3 and potentiated RFX4_v3 transactivation on this promoter through X-box 1, suggesting that the protein-protein interaction was functionally relevant. GPS2 bound to both the carboxyl-terminal region (amino acids 575-735) and the middle region (amino acids 250-574) of the RFX4_v3 protein. RFX4_v3 amino acids 1-574 stimulated the Cx3cl1 promoter to a similar extent as the full-length RFX4_v3 protein; however, deletion of the carboxyl-terminal region of RFX4_v3 impaired the co-activating abilities of GPS2. Based on these data, we conclude that GPS2 interacts with RFX4_v3 to modulate transactivation of genes involved in brain morphogenesis, including Cx3Cl1.
Collapse
Affiliation(s)
- Donghui Zhang
- Laboratories of Respiratory Biology and Neurobiology, Office of Clinical Research, NIEHS, NIH, Research Triangle Park, NC 27709, USA
| | | | | | | |
Collapse
|
41
|
Chao SL, Moss JM, Harry GJ. Lead-induced alterations of apoptosis and neurotrophic factor mRNA in the developing rat cortex, hippocampus, and cerebellum. J Biochem Mol Toxicol 2008; 21:265-72. [PMID: 17912701 PMCID: PMC2366037 DOI: 10.1002/jbt.20191] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previous reports have recently shown the prototypic neurotoxicant, lead, to induce apoptosis in the brains of developing organisms. In the current study, timed-pregnant rats were exposed to lead acetate (0.2% in the drinking water) 24 h following birth at postnatal day 1 (PND 1). Dams and pups were continuously exposed to lead through the drinking water of the dam until PND 20. Postnatal exposure in the pups resulted in altered mRNA levels of the following apoptotic and neurotrophic factors: caspase 2 and 3, bax, bcl-x, brain-derived neurotrophic factor (BDNF). Ribonuclease protection assays were conducted to measure the factors simultaneously at the following postnatal time points: 9, 12, 15, 20, 25, days. Our results suggest a brain region- and time-specific response following lead acetate exposure. The region most vulnerable to alterations occurs in the hippocampus with alterations beginning at PND 12, in which caspase 3, bcl-x, BDNF increase with lead exposure. Significant treatment effects were not observed for both the cortex and cerebellum.
Collapse
Affiliation(s)
- Shirley L Chao
- Department of Natural Sciences, Fayetteville State University, Fayetteville, NC 28301, USA.
| | | | | |
Collapse
|
42
|
Brock B, Basha MR, DiPalma K, Anderson A, Harry GJ, Rice DC, Maloney B, Lahiri DK, Zawia NH. Co-localization and distribution of cerebral APP and SP1 and its relationship to amyloidogenesis. J Alzheimers Dis 2008; 13:71-80. [PMID: 18334759 PMCID: PMC5862394 DOI: 10.3233/jad-2008-13108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alzheimer's disease is characterized by amyloid-beta peptide (Abeta)-loaded plaques in the brain. Abeta is a cleavage fragment of amyloid-beta protein precursor (APP) and over production of APP may lead to amyloidogenesis. The regulatory region of the APP gene contains consensus sites recognized by the transcription factor, specificity protein 1 (SP1), which has been shown to be required for the regulation of APP and Abeta. To understand the role of SP1 in APP biogenesis, herein we have characterized the relative distribution and localization of SP1, APP, and Abeta in various brain regions of rodent and primate models using immunohistochemistry. We observed that overall distribution and cellular localization of SP1, APP, and Abeta are similar and neuronal in origin. Their distribution is abundant in various layers of neocortex, but restricted to the Purkinje cell layer of the cerebellum, and the pyramidal cell layer of hippocampus. These findings suggest that overproduction of Abeta in vivo may be associated with transcriptional pathways involving SP1 and the APP gene.
Collapse
Affiliation(s)
- Brian Brock
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - Md. Riyaz Basha
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - Katie DiPalma
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - Amy Anderson
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| | - G. Jean Harry
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709
| | - Deborah C. Rice
- Maine Department of Health and Human Services, 11 State House Station, Augusta, ME 04333
| | - Bryan. Maloney
- Laboratory for Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Debomoy K. Lahiri
- Laboratory for Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Nasser H. Zawia
- Neurotoxicology and Epigenomics Laboratory, Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881
| |
Collapse
|
43
|
Harry GJ, Funk JA, Lefebvre d'Hellencourt C, McPherson CA, Aoyama M. The type 1 interleukin 1 receptor is not required for the death of murine hippocampal dentate granule cells and microglia activation. Brain Res 2007; 1194:8-20. [PMID: 18191113 DOI: 10.1016/j.brainres.2007.11.076] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 11/18/2007] [Accepted: 11/26/2007] [Indexed: 02/06/2023]
Abstract
Alterations in inflammatory process, neuronal death, and glia response have been observed under manipulation of interleukin-1 (IL-1) and subsequent signaling through the type 1 IL-1 receptor (IL-1R1). To investigate the influence of IL-1R1 activation in the pathophysiology of a chemical-induced injury to the murine hippocampus, we examined the level and pattern of neuronal death and neuroinflammation in male weanling mice exposed to trimethyltin hydroxide (2.0 mg TMT/kg, i.p.). Dentate granule cell death occurred at 6 h post-TMT as detected by active caspase 3 immunostaining and presence of lectin positive microglia. The severity of neuronal death and microglia response increased by 12-24 h with elevations in mRNA levels for TNFalpha and IL-1alpha. In IL-1R1 null (IL-1R1-/-) mice, the pattern and severity of neuronal death at 24 or 72 h post-TMT was similar as compared to wildtype (WT) mice. In both groups, mRNA levels for TNFalpha and MIP-1alpha were elevated, no significant change was seen in either IL-1alpha or IL-1beta, and the early activation of microglia, including their ability to progress to a phagocytic phenotype, was maintained. Compared to WT mice, IL-1R1-/- mice displayed a limited glial fibrillary acidic protein (GFAP) astrocytic response, as well as a preferential induction in mRNA levels of Fas signaling components. Cumulatively, these results indicate that IL-1R1 activation is not necessary for TMT-induced death of dentate granule neurons or local activation of microglia; however, IL-1R1 signaling is involved in mediating the structural response of astrocytes to injury and may regulate apoptotic mechanisms via Fas signaling components.
Collapse
Affiliation(s)
- G Jean Harry
- Neurotoxicology Group, Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
| | | | | | | | | |
Collapse
|
44
|
Abstract
Neurocognitive outcomes of infants born very preterm (less than 32 weeks gestation) remain a major concern in perinatal practice. Very preterm birth rates have increased, with enhanced survival since 1990. As focal brain lesions become less common, diffuse injury to both gray and white matter is now the primary focus for improving neurologic outcomes in survivors. Recent evidence supports preoligodendrocytes as the principal cellular target of diffuse white matter injury due to their susceptibility to hypoxic-ischemic and inflammatory insults. An understanding of their development and vulnerability can inform acute nursing care of very preterm infants.
Collapse
Affiliation(s)
- Susan H Brunssen
- School of Nursing and Neurodevelopmental Disorders Research Center, School of Medicine at the University of North Carolina at Chapel Hill, NC 27599-7460, USA.
| | | |
Collapse
|
45
|
Lein PJ, Yang D, Bachstetter AD, Tilson HA, Harry GJ, Mervis RF, Kodavanti PRS. Ontogenetic alterations in molecular and structural correlates of dendritic growth after developmental exposure to polychlorinated biphenyls. Environ Health Perspect 2007; 115:556-63. [PMID: 17450224 PMCID: PMC1852648 DOI: 10.1289/ehp.9773] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Accepted: 01/16/2007] [Indexed: 05/03/2023]
Abstract
OBJECTIVE Perinatal exposure to polychlorinated biphenyls (PCBs) is associated with decreased IQ scores, impaired learning and memory, psychomotor difficulties, and attentional deficits in children. It is postulated that these neuropsychological deficits reflect altered patterns of neuronal connectivity. To test this hypothesis, we examined the effects of developmental PCB exposure on dendritic growth. METHODS Rat dams were gavaged from gestational day 6 through postnatal day (PND) 21 with vehicle (corn oil) or the commercial PCB mixture Aroclor 1254 (6 mg/kg/day). Dendritic growth and molecular markers were examined in pups during development. RESULTS Golgi analyses of CA1 hippocampal pyramidal neurons and cerebellar Purkinje cells indicated that developmental exposure to PCBs caused a pronounced age-related increase in dendritic growth. Thus, even though dendritic lengths were significantly attenuated in PCB-treated animals at PND22, the rate of growth was accelerated at later ages such that by PND60, dendritic growth was comparable to or even exceeded that observed in vehicle controls. Quantitative reverse transcriptase polymerase chain reaction analyses demonstrated that from PND4 through PND21, PCBs generally increased expression of both spinophilin and RC3/neurogranin mRNA in the hippocampus, cerebellum, and cortex with the most significant increases observed in the cortex. CONCLUSIONS This study demonstrates that developmental PCB exposure alters the ontogenetic profile of dendritogenesis in critical brain regions, supporting the hypothesis that disruption of neuronal connectivity contributes to neuropsychological deficits seen in exposed children.
Collapse
Affiliation(s)
- Pamela J. Lein
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, Oregon, USA
| | - Dongren Yang
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, Oregon, USA
| | - Adam D. Bachstetter
- Neurostructural Research Labs, Tampa, Florida, USA
- Center of Excellence for Aging and Brain Repair and Department of Neurosurgery, University of South Florida College of Medicine, Tampa, Florida, USA
| | - Hugh A. Tilson
- Cellular and Molecular Toxicology Branch, Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - G. Jean Harry
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Ronald F. Mervis
- Neurostructural Research Labs, Tampa, Florida, USA
- Center of Excellence for Aging and Brain Repair and Department of Neurosurgery, University of South Florida College of Medicine, Tampa, Florida, USA
| | - Prasada Rao S. Kodavanti
- Cellular and Molecular Toxicology Branch, Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| |
Collapse
|
46
|
Abstract
Studies examining maternal infection as a risk factor for neurological disorders in the offspring have suggested that altered maternal immune status during pregnancy can be considered as an adverse event in prenatal development. Infection occurring in the mother during the gestational period has been implicated in multiple neurological effects. The current manuscript will consider the issue of immune/inflammatory conditions during prenatal development where adverse outcomes have been linked to maternal systemic infection. The discussions will focus primary on white matter and oligodendrocytes as they have been identified as target processes. This white matter damage occurs in very early preterm infants and in various other human diseases currently being examined for a linkage to maternal or early developmental immune status. The intent is to draw attention to the impact of altered immune status during pregnancy on the offspring for the consideration of such contributing factors to the general assessment of developmental neurotoxicology.
Collapse
Affiliation(s)
- G Jean Harry
- Neurotoxicology Group, Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health/DHHS, Research Triangle Park, NC 27709, USA.
| | | | | |
Collapse
|
47
|
Weerasinghe GR, Coon SL, Bhattacharjee AK, Harry GJ, Bosetti F. Regional protein levels of cytosolic phospholipase A2 and cyclooxygenase-2 in Rhesus monkey brain as a function of age. Brain Res Bull 2006; 69:614-21. [PMID: 16716827 PMCID: PMC1473171 DOI: 10.1016/j.brainresbull.2006.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 12/30/2005] [Accepted: 03/06/2006] [Indexed: 10/24/2022]
Abstract
Limited evidence suggests that brain cytosolic phospholipase A(2) (cPLA(2)), which selectively releases arachidonic acid (AA) from membrane phospholipids, and cyclooxygenase-2 (COX-2), the rate-limiting enzyme for AA metabolism to prostanoids, change as a function of normal aging. In this study, we examined the protein levels of cPLA(2) and COX-2 enzymes in hippocampus, frontal pole and cerebellum from young (2-5 years old), middle-aged (8-11 years old) and old (23 years old) male and female Rhesus monkeys. In the cerebellum, cPLA(2) protein level was higher in the young brain as compared to levels seen at both middle-aged and old. Similarly, in the frontal pole, the young brain showed a higher level of COX-2 protein as compared to the levels seen at both older ages. For both, once an animal reached 8-11 years of age the levels appeared to remain relatively constant over the next decade. Immunohistochemistry of COX-2 protein within the brain demonstrated no significant change in the localization to neurons within the frontal pole. Qualitatively, a greater number of neurons were positively stained for COX-2 in the young brain than in the aged brain. Based on the previous reports of localization of cPLA(2) and COX-2 at post-synaptic sites in neurons results from the current study suggest that the elevated protein levels of the two enzymes seen in the younger brain is related to the greater potential for synaptic plasticity across multiple neurons as a function of age and that cPLA(2) and COX-2 may be considered as post-synaptic markers.
Collapse
Affiliation(s)
- Gayani R. Weerasinghe
- Brain Physiology and Metabolism Section, National Institute on Aging, NIH, Bethesda, MD 20892, USA
| | - Steven L. Coon
- Section on Neuroendocrinology, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | | | - G. Jean Harry
- Neurotoxicology Group, National Institute of Environmental Health Sciences , NIH, Research Triangle Park, NC 27709, USA
| | - Francesca Bosetti
- Brain Physiology and Metabolism Section, National Institute on Aging, NIH, Bethesda, MD 20892, USA
- *Corresponding author: Brain Physiology and Metabolism Section, NIA, NIH; 9 Memorial Drive, Bldg. 9, Rm. 1S126, Bethesda, MD 20892-0947, USA. Tel: (301) 594-5077; Fax: (301) 402-0074; E-mail:
| |
Collapse
|
48
|
Sills RC, Harry GJ, Valentine WM, Morgan DL. Interdisciplinary neurotoxicity inhalation studies: Carbon disulfide and carbonyl sulfide research in F344 rats. Toxicol Appl Pharmacol 2005; 207:245-50. [PMID: 16002115 DOI: 10.1016/j.taap.2005.02.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2004] [Revised: 02/16/2005] [Accepted: 02/17/2005] [Indexed: 11/18/2022]
Abstract
Inhalation studies were conducted on the hazardous air pollutants, carbon disulfide, which targets the central nervous system (spinal cord) and peripheral nervous system (distal portions of long myelinated axons), and carbonyl sulfide, which targets the central nervous system (brain). The objectives were to investigate the neurotoxicity of these compounds by a comprehensive evaluation of function, structure, and mechanisms of disease. Through interdisciplinary research, the major finding in the carbon disulfide inhalation studies was that carbon disulfide produced intra- and intermolecular protein cross-linking in vivo. The observation of dose-dependent covalent cross-linking in neurofilament proteins prior to the onset of lesions is consistent with this process contributing to the development of the neurofilamentous axonal swellings characteristic of carbon disulfide neurotoxicity. Of significance is that valine-lysine thiourea cross-linking on rat globin and lysine-lysine thiourea cross-linking on erythrocyte spectrin reflect cross-linking events occurring within the axon and could potentially serve as biomarkers of carbon disulfide exposure and effect. In the carbonyl sulfide studies, using magnetic resonance microscopy (MRM), we determined that carbonyl sulfide targets the auditory pathway in the brain. MRM allowed the examination of 200 brain slices and made it possible to identify the most vulnerable sites of neurotoxicity, which would have been missed in our traditional neuropathology evaluations. Electrophysiological studies were focused on the auditory system and demonstrated decreases in auditory brain stem evoked responses. Similarly, mechanistic studies focused on evaluating cytochrome oxidase activity in the posterior colliculus and parietal cortex. A decrease in cytochrome oxidase activity was considered to be a contributing factor to the pathogenesis of carbonyl sulfide neurotoxicity.
Collapse
Affiliation(s)
- Robert C Sills
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, 111 Alexander Drive, South Campus, MD B3-08, PO Box 12233, Research Triangle Park, NC 27709, USA.
| | | | | | | |
Collapse
|
49
|
Lefebvre d'Hellencourt C, Harry GJ. Molecular profiles of mRNA levels in laser capture microdissected murine hippocampal regions differentially responsive to TMT-induced cell death. J Neurochem 2005; 93:206-20. [PMID: 15773920 DOI: 10.1111/j.1471-4159.2004.03017.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Using a chemical-induced model of dentate granule (DG) cell death, cDNA microarray analysis was used to identify gene profiles from the laser-captured microdissected (LCM) hippocampal DG cell region versus the CA pyramidal cell layer (CA) from 21-day-old male CD1 mice injected with trimethyltin hydroxide (TMT; 3.0 mg/kg, i.p.). At 6 h post-TMT, lectin + microglia displaying a reactive morphology were in contact with active caspase 3+ neurons. By 18 h, amoeboid microglia and signs of phagocytosis, and a mild astrocytic response were present in the DG. There was no evidence of IgG extravasation in the hippocampus, or cell death and glial reactivity in the CA. Atlas 1.2K Clontech array detected 115 genes changed in the hippocampus with TMT and included genes associated with immediate-early responses, calcium homeostasis, cellular signaling, cell cycle, immunomodulation and DNA repair. Early responses localized to LCM DG samples consisted of elevations in inflammatory factors such as tumor necrosis factor-alpha and receptors, as well as MIP1alpha, CD14, CD18, and a decrease in factors associated with calcium buffering. By 18 h, in the DG, changes occurred in transcripts associated with apoptosis, cell adhesion, DNA repair, cell proliferation and growth. In the CA, a differential level of elevation was seen in CD86 antigen, zinc finger protein 38 and DNA damage inducible transcript 3. A significant number of genes was decreased at these early time points in both hippocampal regions.
Collapse
Affiliation(s)
- Christian Lefebvre d'Hellencourt
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Health and Human Services, Research Triangle Park, North Carolina 27709, USA
| | | |
Collapse
|
50
|
Harry GJ, Harris MW, Burka LT. Mercury concentrations in brain and kidney following ethylmercury, methylmercury and Thimerosal administration to neonatal mice. Toxicol Lett 2004; 154:183-9. [PMID: 15501610 DOI: 10.1016/j.toxlet.2004.07.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Revised: 07/28/2004] [Accepted: 07/28/2004] [Indexed: 10/26/2022]
Abstract
The distribution of mercury to the brain following an injection of methylmercury (MeHg) or ethylmercury (EtHg) was examined in immature mice. Postnatal day (PND) 16 CD1 mice received MeHg chloride either by IM injection or by gavage. At 24 h and 7 days post-injection, total mercury concentrations were determined in blood, kidney, brain, and muscle by cold vapor atomic fluorescence spectrometry. At 24 h, an IM injection of MeHg chloride (17.4 microg) produced total mercury concentrations in the blood (6.2 +/- 0.9 microg/g), brain (5.6 +/- 1.3 microg; 0.6% delivered dose), and kidney (25.2 +/- 5.6 microg; 1.1%), approximately 30% of that obtained from oral administration (blood: 17.9 +/- 1.0 microg; brain: 16.1 +/- 1.2 microg, 1.5%; kidney: 64.9 +/- 6.3 microg, 2.7%). For comparison, PND 16 mice received an IM injection of concentrated dosing suspensions (2 microl dosing vol.) for EtHg chloride (6 microg) or Thimerosal (15.4 microg). For EtHg, approximately 0.39 +/- 0.06% of the injected mercury was detected in the brain and 3.5 +/- 0.6% in the kidney at 24 h. Thimerosal IM injection resulted in 0.22 +/- 0.04% in the brain, and 1.7 +/- 0.3% in the kidney. By 7 days, mercury levels decreased in the blood but were unchanged in the brain. An acute IM injection to adult mice of each suspension at a 10-fold higher dose resulted an average 0.1% mercury in the brain, and higher levels in the blood, kidney, and muscle as compared to the young. In immature mice, MeHg delivered via oral route of administration resulted in significantly greater tissue levels as compared to levels from IM injection. Comparisons of tissue distribution following IM administration suggest that an oral route of administration for mercury is not comparable to an IM delivery and that MeHg does not appear to be a good model for EtHg-containing compounds.
Collapse
Affiliation(s)
- G Jean Harry
- Laboratory of Neurobiology, Neurotoxicology Group, National Institute of Environmental Health Sciences, P.O. Box 12233, MD C1-04, Research Triangle Park, NC 27709, USA.
| | | | | |
Collapse
|